Membrane topology of Golgi-localized probable S-adenosylmethionine-dependent methyltransferase in tobacco (Nicotiana tabacum) BY-2 cells.

Science.gov (United States)

Liu, Jianping; Hayashi, Kyoko; Matsuoka, Ken

2015-01-01

S-adenosylmethionine (SAM)-dependent methyltransferases (MTases) transfer methyl groups to substrates. In this study, a novel putative tobacco SAM-MTase termed Golgi-localized methyl transferase 1 (GLMT1) has been characterized. GLMT1 is comprised of 611 amino acids with short N-terminal region, putative transmembrane region, and C-terminal SAM-MTase domain. Expression of monomeric red fluorescence protein (mRFP)-tagged protein in tobacco BY-2 cell indicated that GLMT1 is a Golgi-localized protein. Analysis of the membrane topology by protease digestion suggested that both C-terminal catalytic region and N-terminal region seem to be located to the cytosolic side of the Golgi apparatus. Therefore, GLMT1 might have a different function than the previously studied SAM-MTases in plants.

Genetics of Progressive Supranuclear Palsy

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Sun Young Im

2015-09-01

Full Text Available Progressive supranuclear palsy (PSP is a neurodegenerative syndrome that is clinically characterized by progressive postural instability, supranuclear gaze palsy, parkinsonism and cognitive decline. Pathologically, diagnosis of PSP is based on characteristic features, such as neurofibrillary tangles, neutrophil threads, tau-positive astrocytes and their processes in basal ganglia and brainstem, and the accumulation of 4 repeat tau protein. PSP is generally recognized as a sporadic disorder; however, understanding of genetic background of PSP has been expanding rapidly. Here we review relevant publications to outline the genetics of PSP. Although only small number of familial PSP cases have been reported, the recognition of familial PSP has been increasing. In some familial cases of clinically probable PSP, PSP pathologies were confirmed based on NINDS neuropathological diagnostic criteria. Several mutations in MAPT, the gene that causes a form of familial frontotemporal lobar degeneration with tauopathy, have been identified in both sporadic and familial PSP cases. The H1 haplotype of MAPT is a risk haplotype for PSP, and within H1, a sub-haplotype (H1c is associated with PSP. A recent genome-wide association study on autopsyproven PSP revealed additional PSP risk alleles in STX6 and EIF2AK3. Several heredodegenerative parkinsonian disorders are referred to as PSP-look-alikes because their clinical phenotype, but not their pathology, mimics PSP. Due to the fast development of genomics and bioinformatics, more genetic factors related to PSP are expected to be discovered. Undoubtedly, these studies will provide a better understanding of the pathogenesis of PSP and clues for developing therapeutic strategies.

Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

International Nuclear Information System (INIS)

Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo

1989-01-01

Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author)

Computed tomographic findings in progressive supranuclear palsy

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Saitoh, H; Yoshii, F; Shinohara, Y

1987-03-01

CT findings of 6 patients with progressive supranuclear palsy (PSP) are described, with emphasis on their supratentorial changes in comparison with those of control subjects and patients with Parkinson's disease (PD). As estimated from CT films, the lateral ventricles, third ventricle and prepontine cistern were significantly enlarged in PSP patients compared with both controls and PD patients. It is suggested that the patients with PSP have not only infratentorial but also supratentorial lesions.

Voltage-Dependent Intrinsic Bursting in Olfactory Bulb Golgi Cells

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Pressler, R. Todd; Rozman, Peter A.; Strowbridge, Ben W.

2013-01-01

In the mammalian olfactory bulb (OB), local synaptic circuits modulate the evolving pattern of activity in mitral and tufted cells following olfactory sensory stimulation. GABAergic granule cells, the most numerous interneuron subtype in this brain region, have been extensively studied. However, classic studies using Golgi staining methods…

cis-Golgi proteins accumulate near the ER exit sites and act as the scaffold for Golgi regeneration after brefeldin A treatment in tobacco BY-2 cells.

Science.gov (United States)

Ito, Yoko; Uemura, Tomohiro; Shoda, Keiko; Fujimoto, Masaru; Ueda, Takashi; Nakano, Akihiko

2012-08-01

The Golgi apparatus forms stacks of cisternae in many eukaryotic cells. However, little is known about how such a stacked structure is formed and maintained. To address this question, plant cells provide a system suitable for live-imaging approaches because individual Golgi stacks are well separated in the cytoplasm. We established tobacco BY-2 cell lines expressing multiple Golgi markers tagged by different fluorescent proteins and observed their responses to brefeldin A (BFA) treatment and BFA removal. BFA treatment disrupted cis, medial, and trans cisternae but caused distinct relocalization patterns depending on the proteins examined. Medial- and trans-Golgi proteins, as well as one cis-Golgi protein, were absorbed into the endoplasmic reticulum (ER), but two other cis-Golgi proteins formed small punctate structures. After BFA removal, these puncta coalesced first, and then the Golgi stacks regenerated from them in the cis-to-trans order. We suggest that these structures have a property similar to the ER-Golgi intermediate compartment and function as the scaffold of Golgi regeneration.

Sequential phosphorylation of GRASP65 during mitotic Golgi disassembly

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Danming Tang

2012-09-01

GRASP65 phosphorylation during mitosis and dephosphorylation after mitosis are required for Golgi disassembly and reassembly during the cell cycle. At least eight phosphorylation sites on GRASP65 have been identified, but whether they are modified in a coordinated fashion during mitosis is so far unknown. In this study, we raised phospho-specific antibodies that recognize phosphorylated T220/T224, S277 and S376 residues of GRASP65, respectively. Biochemical analysis showed that cdc2 phosphorylates all three sites, while plk1 enhances the phosphorylation. Microscopic studies using these antibodies for double and triple labeling demonstrate sequential phosphorylation and dephosphorylation during the cell cycle. S277 and S376 are phosphorylated from late G2 phase through metaphase until telophase when the new Golgi is reassembled. T220/224 is not modified until prophase, but is highly modified from prometaphase to anaphase. In metaphase, phospho-T220/224 signal localizes on both Golgi haze and mitotic Golgi clusters that represent dispersed Golgi vesicles and Golgi remnants, respectively, while phospho-S277 and S376 labeling is more concentrated on mitotic Golgi clusters. Expression of a phosphorylation-resistant GRASP65 mutant T220A/T224A inhibited mitotic Golgi fragmentation to a much larger extent than the expression of the S277A and S376A mutants. In cytokinesis, T220/224 dephosphorylation occurs prior to that of S277, but after S376. This study provides evidence that GRASP65 is sequentially phosphorylated and dephosphorylated during mitosis at different sites to orchestrate Golgi disassembly and reassembly during cell division, with phosphorylation of the T220/224 site being most critical in the process.

Mena–GRASP65 interaction couples actin polymerization to Golgi ribbon linking

Science.gov (United States)

Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

2016-01-01

In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. PMID:26538023

Presentation of a patient carrying a progressive supra-nuclear paralysis

International Nuclear Information System (INIS)

Arredondo Bruce, Alfredo; Huerta Ramírez, Janet; Domínguez Calderón, Tomás; Pérez Zayas, Jesús

2016-01-01

The progressive supra-nuclear paralysis (PSP) or Steele-Richardson-Olszewsky’s syndrome is a strange, degenerative illness produced by the deterioration and gradual death of brain selected areas. We present the case of a female patient, aged 80 years, who refers postural instability, frequent falls and cognitive dysfunctions. She also presents stiffness in retrocollis in the back of the neck, fall of eyelids, left hand shaking, dysarthric and incoherent language, and shaking of both hands in coins counting. The cardiovascular examination showed 2nd increased beat, systolic murmur III/IV in mitral focus, AT 160/90 mm of Hg, edemas in both inferior members, hearth frequency of 110 beats/min., and jugular ingurgitation. The rest of the physical examination was normal. The etiologic diagnosis was progressive supranuclear paralysis and dilated cardiomyopathy. The tau protein is important in the maintenance of the neuronal morphology through microtubules formation, the different proportions and locations, causing the Richardson’s syndrome. The most common symptoms of this entity are postural instability and frequent falls, dysarthria, hypokinesia and visual alterations. Magnetic resonance and functional neuroimaging help the diagnosis. (author)

The small G protein Arl5 contributes to endosome-to-Golgi traffic by aiding the recruitment of the GARP complex to the Golgi

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Cláudia Rosa-Ferreira

2015-03-01

Full Text Available The small G proteins of the Arf family play critical roles in membrane trafficking and cytoskeleton organization. However, the function of some members of the family remains poorly understood including Arl5 which is widely conserved in eukaryotes. Humans have two closely related Arl5 paralogues (Arl5a and Arl5b, and both Arl5a and Arl5b localize to the trans-Golgi with Arl5b being involved in retrograde traffic from endosomes to the Golgi apparatus. To investigate the function of Arl5, we have used Drosophila melanogaster as a model system. We find that the single Arl5 orthologue in Drosophila also localizes to the trans-Golgi, but flies lacking the Arl5 gene are viable and fertile. By using both liposome and column based affinity chromatography methods we find that Arl5 interacts with the Golgi-associated retrograde protein (GARP complex that acts in the tethering of vesicles moving from endosomes to the trans-Golgi network (TGN. In Drosophila tissues the GARP complex is partially displaced from the Golgi when Arl5 is absent, and the late endosomal compartment is enlarged. In addition, in HeLa cells GARP also becomes cytosolic upon depletion of Arl5b. These phenotypes are consistent with a role in endosome-to-Golgi traffic, but are less severe than loss of GARP itself. Thus it appears that Arl5 is one of the factors that directs the recruitment of the GARP complex to the trans-Golgi, and this function is conserved in both flies and humans.

Identification of common variants influencing risk of the tauopathy progressive supranuclear palsy

NARCIS (Netherlands)

G. Hoglinger (Gunter); N.M. Melhem (Nadine); D. Dickson (Dennis); P.M.A. Sleiman (Patrick); L.-S. Wang; L. Klei (Lambertus); R. Rademakers (Rosa); R. de Silva (Rohan); I. Litvan (Irene); D.E. Riley (David); J.C. van Swieten (John); P. Heutink (Peter); Z.K. Wszolek (Zbigniew); R.J. Uitti (Ryan); J. Vandrovcova (Jana); H.I. Hurtig (Howard); R.G. Gross (Rachel); W. Maetzler (Walter); S. Goldwurm (Stefano); E. Tolosa; B. Borroni (Barbara); P. Pastor (Pau); L.B. Cantwell (Laura); M.R. Han; A. Dillman (Allissa); M.P. van der Brug (Marcel); J. Gibbs (Raphael); M.R. Cookson (Mark); D.G. Hernandez (Dena); A. Singleton (Andrew); M.J. Farrer (Matthew); C.-E. Yu (Changen); L.I. Golbe (Lawrence); T. Revesz (Tamas); J. Hardy (John); A.J. Lees (Andrew); B. Devlin (Bernie); H. Hakonarson (Hakon); U. Müller (Ulrich); G.D. Schellenberg (Gerard); R.L. Albin (Roger); E. Alonso (Elena); M. Apfelbacher (Manuela); S.E. Arnold (Steven); J. Avila (Jesús); T.G. Beach (Thomas); S. Beecher (Sherry); D. Berg (Daniela); T.D. Bird (Thomas); N. Bogdanović (Nenad); A.J.W. Boon (Andrea); Y. Bordelon (Yvette); A. Brice (Alexis); H. Budka (Herbert); M. Canesi (Margherita); W.Z. Chiu (Wang Zheng); R. Cilia (Roberto); C. Colosimo (Carlo); P.P. de Deyn (Peter); J.G. de Yebenes; L. Donker Kaat (Laura); R. Duara (Ranjan); A. Durr; S. Engelborghs (Sebastiaan); G. Fabbrini (Giovanni); N.A. Finch (Nicole); R. Flook (Robyn); M.P. Frosch (Matthew); C. Gaig; D. Galasko (Douglas); T. Gasser (Thomas); M. Gearing (Marla); E.T. Geller (Evan); B. Ghetti (Bernardino); N.R. Graff-Radford (Neill); M. Grossman (Murray); D.A. Hall (Deborah); L.-N. Hazrati; M. Höllerhage (Matthias); J. Jankovic (Joseph); J.L. Juncos (Jorge); A. Karydas (Anna); H.A. Kretzschmar (Hans); I. Leber (Isabelle); V.M.Y. Lee (Virginia); A.P. Lieberman (Andrew); K.E. Lyons (Kelly); C. Mariani (Claudio); E. Masliah (Eliezer); L.A. Massey (Luke); C.A. McLean (Catriona); N. Meucci (Nicoletta); B.L. Miller (Bruce); B. Mollenhauer (Brit); J.C. Möller (Jens); H. Morris (Huw); S.S. O'Sullivan (Sean); W. Oertel; D. Ottaviani (Donatella); A. Padovani (Alessandro); R. Pahwa (Rajesh); G. Pezzoli (Gianni); S. Pickering-Brown (Stuart); W. Poewe (Werner); A. Rabano (Alberto); A. Rajput (Alex); S.G. Reich (Stephen); G. Respondek (Gesine); S. Roeber (Sigrun); J.D. Rohrer (Jonathan Daniel); O.A. Ross (Owen); M. Rossor (Martin); G. Sacilotto (Giorgio); W.W. Seeley (William); K. Seppi (Klaus); L. Silveira-Moriyama (Laura); S. Spina (Salvatore); K. Srulijes (Karin); P. St. George-Hyslop (Peter); M. Stamelou (Maria); D.G. Standaert (David); S. Tesei (Silvana); W.W. Tourtellotte (Wallace); C. Trenkwalder (Claudia); C. Troakes (Claire); J.Q. Trojanowski (John); J.C. Troncoso (Juan); V.M. Deerlin (Vivianna); J.P.G. Vonsattel; G.K. Wenning (Gregor); C.L. White III (Charles); P. Winter (Pia); C. Zarow (Chris); A.L. Zecchinelli (Anna); A. Antonini (Angelo)

2011-01-01

textabstractProgressive supranuclear palsy (PSP) is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated

Identification of common variants influencing risk of the tauopathy progressive supranuclear palsy

NARCIS (Netherlands)

Hoglinger, G.U.; Melhem, N.M.; Dickson, D.W.; Sleiman, P.M.A.; Wang, L.S.; Klei, L.; Rademakers, R.; de Silva, R.; Litvan, I.; Riley, D.E.; van Swieten, J.C.; Heutink, P.; Wszolek, Z.K.; Uitti, R.J.; Vandrovcova, J.; Hurtig, H.I.; Gross, R.G.; Maetzler, W.; Goldwurm, S.; Tolosa, E.; Borroni, B.; Pastor, P.; Cantwell, L.B.; Han, M.R.; Dillman, A.; van der Brug, M.P.; Gibbs, J.R.; Cookson, M.R.; Hernandez, D.G.; Singleton, A.B.; Farrer, M.J.; Yu, C.E.; Golbe, L.I.; Revesz, T.; Hardy, J.; Lees, A.J.; Devlin, B.; Hakonarson, H.; Muller, U.; Schellenberg, G.D.

2011-01-01

Progressive supranuclear palsy (PSP) is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some

The role of Golgi reassembly and stacking protein 65 phosphorylation in H2O2-induced cell death and Golgi morphological changes.

Science.gov (United States)

Ji, Guang; Zhang, Weiwei; Quan, Moyuan; Chen, Yang; Qu, Hui; Hu, Zhiping

2016-12-01

This study aimed to investigate the effects of H 2 O 2 -induced oxidative stress on cell viability and survival, as well as changes in the distribution of Golgi apparatus and in the level of Golgi reassembly and stacking protein 65 (GRASP65). Cell viability of cultured N2a cells treated with H 2 O 2 was measured by the MTT assay. Apoptosis was measured by flow cytometry analyses. Cells labeled by indirect immunofluorescence were observed under confocal microscope to detect any Golgi morphological alterations; electron microscopy of Golgi apparatus was also done. Expression of GRASP65 and phospho-GRASP65 was examined by immunoblotting. H 2 O 2 treatment reduced the cell viability and raised the cell mortality of N2a cells in a time-dependent manner. Notable changes were only observed in the distribution and morphology of Golgi apparatus at 6 h after H 2 O 2 treatment. The expression of GRASP65 showed no significant changes at different time points; the phosphorylated GRASP65 level was significantly increased after H 2 O 2 treatment, peaked at 3 h, and finally dropped at 6 h. Taken together, GRASP65 phosphorylation may have a critical role in inducing cell death at the early stage after H 2 O 2 treatment, while its role in H 2 O 2 -induced Golgi morphological changes may be complex.

Phosphorylation of p37 is important for Golgi disassembly at mitosis

International Nuclear Information System (INIS)

Kaneko, Yayoi; Tamura, Kaori; Totsukawa, Go; Kondo, Hisao

2010-01-01

Research highlights: → p37 is phosphorylated on Serine-56 and Threonine-59 by Cdc2 at mitosis. → Phosphorylated p37 does not bind to Golgi membranes. → p37 phosphorylation inhibits p97/p37-mediated Golgi membrane fusion. -- Abstract: In mammals, the Golgi apparatus is disassembled at early mitosis and reassembled at the end of mitosis. For Golgi disassembly, membrane fusion needs to be blocked. Golgi biogenesis requires two distinct p97ATPase-mediated membrane fusion, the p97/p47 and p97/p37 pathways. We previously reported that p47 phosphorylation on Serine-140 by Cdc2 results in mitotic inhibition of the p97/p47 pathway . In this study, we demonstrate that p37 is phosphorylated on Serine-56 and Threonine-59 by Cdc2 at mitosis, and this phosphorylated p37 does not bind to Golgi membranes. Using an in vitro Golgi reassembly assay, we show that mutated p37(S56D, T59D), which mimics mitotic phosphorylation, does not cause any cisternal regrowth, indicating that p37 phosphorylation inhibits the p97/p37 pathway. Our results demonstrate that p37 phosphorylation on Serine-56 and Threonine-59 is important for Golgi disassembly at mitosis.

Mena-GRASP65 interaction couples actin polymerization to Golgi ribbon linking.

Science.gov (United States)

Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

2016-01-01

In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. © 2016 Tang et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Determinants for membrane association and permeabilization of the coxsackievirus 2B protein and the identification of the Golgi complex as the target organelle.

Science.gov (United States)

de Jong, Arjan S; Wessels, Els; Dijkman, Henri B P M; Galama, Jochem M D; Melchers, Willem J G; Willems, Peter H G M; van Kuppeveld, Frank J M

2003-01-10

The 2B protein of enterovirus is responsible for the alterations in the permeability of secretory membranes and the plasma membrane in infected cells. The structural requirements for the membrane association and the subcellular localization of this essential virus protein, however, have not been defined. Here, we provide evidence that the 2B protein is an integral membrane protein in vivo that is predominantly localized at the Golgi complex upon individual expression. Addition of organelle-specific targeting signals to the 2B protein revealed that the Golgi localization is an absolute prerequisite for the ability of the protein to modify plasma membrane permeability. Expression of deletion mutants and heterologous proteins containing specific domains of the 2B protein demonstrated that each of the two hydrophobic regions could mediate membrane binding individually. However, the presence of both hydrophobic regions was required for the correct membrane association, efficient Golgi targeting, and the membrane-permeabilizing activity of the 2B protein, suggesting that the two hydrophobic regions are cooperatively involved in the formation of a membrane-integral complex. The formation of membrane-integral pores by the 2B protein in the Golgi complex and the possible mechanism by which a Golgi-localized virus protein modifies plasma membrane permeability are discussed.

Accuracy of MR markers for differentiating Progressive Supranuclear Palsy from Parkinson's disease

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Stefano Zanigni

2016-01-01

Conclusion: Although several quantitative brain MR markers provided high diagnostic accuracy in differentiating Progressive Supranuclear Palsy-Richardson's Syndrome from Parkinson's disease, the morphometric assessment of midbrain area is the best single diagnostic marker and should be routinely included in the neuroradiological work-up of parkinsonian patients.

Progressive Supranuclear Palsy and Corticobasal Degeneration: Pathophysiology and Treatment Options

OpenAIRE

Lamb, Ruth; Rohrer, Jonathan D.; Lees, Andrew J.; Morris, Huw R.

2016-01-01

Opinion statement There are currently no disease-modifying treatments for progressive supranuclear palsy (PSP) or corticobasal degeneration (CBD), and no approved pharmacological or therapeutic treatments that are effective in controlling their symptoms. The use of most pharmacological treatment options are based on experience in other disorders or from non-randomized historical controls, case series, or expert opinion. Levodopa may provide some improvement in symptoms of Parkinsonism (specif...

Progressive Supranuclear Palsy and Corticobasal Degeneration: Pathophysiology and Treatment Options

OpenAIRE

Lamb, R.; Rohrer, J. D.; Lees, A. J.; Morris, H. R.

2016-01-01

There are currently no disease-modifying treatments for progressive supranuclear palsy (PSP) or corticobasal degeneration (CBD), and no approved pharmacological or therapeutic treatments that are effective in controlling their symptoms. The use of most pharmacological treatment options are based on experience in other disorders or from non-randomized historical controls, case series, or expert opinion. Levodopa may provide some improvement in symptoms of Parkinsonism (specifically bradykinesi...

The trans-Golgi Network and the Golgi Stacks Behave Independently During Regeneration After Brefeldin A Treatment in Tobacco BY-2 Cells.

Science.gov (United States)

Ito, Yoko; Toyooka, Kiminori; Fujimoto, Masaru; Ueda, Takashi; Uemura, Tomohiro; Nakano, Akihiko

2017-04-01

The trans-Golgi network (TGN) plays an essential role in intracellular membrane trafficking. In plant cells, recent live-cell imaging studies have revealed the dynamic behavior of the TGN independent from the Golgi apparatus. In order to better understand the relationships between the two organelles, we examined their dynamic responses to the reagent brefeldin A (BFA) and their recovery after BFA removal. Golgi markers responded to BFA similarly over a range of concentrations, whereas the behavior of the TGN was BFA concentration dependent. The TGN formed aggregates at high concentrations of BFA; however, TGN proteins relocalized to numerous small vesicular structures dispersed throughout the cytoplasm at lower BFA concentrations. During recovery from weak BFA treatment, the TGN started to regenerate earlier than the completion of the Golgi. The regeneration of the two organelles proceeded independently of each other for a while, and eventually was completed by their association. Our data suggest that there is some degree of autonomy for the regeneration of the TGN and the Golgi in tobacco BY-2 cells. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Aspiration pneumonia and bronchopneumonia in progressive supranuclear palsy treated with qing fei tang: two case reports.

Science.gov (United States)

Nozaki, Ichiro; Kato-Motozaki, Yuko; Ikeda, Tokuhei; Takahashi, Kazuya; Tagami, Atsuro; Ishida, Chiho; Komai, Kiyonobu

2015-03-26

Qing fei tang, which is used for various respiratory diseases, is useful for reducing relapse of aspiration pneumonia and bronchopneumonia in stroke, but the effect remains unknown in Parkinson's syndrome. We report two cases of Japanese patients with progressive supranuclear palsy and relapsing aspiration pneumonia and bronchopneumonia, which was successfully prevented by qing fei tang. Two Japanese men with progressive supranuclear palsy and receiving total enteral feeding (patient one (66-years-old) and patient two (76-years-old)) had experienced recurrent aspiration pneumonia and bronchopneumonia, which was unresponsive to conventional therapy. The respiratory infection developed twice at intervals of two months in patient one, and nine times at almost monthly intervals in patient two. Thereafter, they were given qing fei tang. After administration of qing fei tang, the respiratory infection reoccurred only once; after 5.5 months for patient one, and six months for patient two. Both of our patients clearly showed a reduced incidence of respiratory infection. Both of our patients clearly showed a reduced incidence of respiratory infection after the administration of qing fei tang. Qing fei tang could be useful for the prevention of recurrent aspiration pneumonia and bronchopneumonia in progressive supranuclear palsy.

The Cirque du Soleil of Golgi membrane dynamics.

Science.gov (United States)

Bankaitis, Vytas A

2009-07-27

The role of lipid metabolic enzymes in Golgi membrane remodeling is a subject of intense interest. Now, in this issue, Schmidt and Brown (2009. J. Cell Biol. doi:10.1083/jcb.200904147) report that lysophosphatidic acid-specific acyltransferase, LPAAT3, contributes to Golgi membrane dynamics by suppressing tubule formation.

The Cirque du Soleil of Golgi membrane dynamics

OpenAIRE

Bankaitis, Vytas A.

2009-01-01

The role of lipid metabolic enzymes in Golgi membrane remodeling is a subject of intense interest. Now, in this issue, Schmidt and Brown (2009. J. Cell Biol. doi:10.1083/jcb.200904147) report that lysophosphatidic acid?specific acyltransferase, LPAAT3, contributes to Golgi membrane dynamics by suppressing tubule formation.

Regulation of ER-Golgi Transport Dynamics by GTPases in Budding Yeast

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Yasuyuki Suda

2018-01-01

Full Text Available A large number of proteins are synthesized de novo in the endoplasmic reticulum (ER. They are transported through the Golgi apparatus and then delivered to their proper destinations. The ER and the Golgi play a central role in protein processing and sorting and show dynamic features in their forms. Ras super family small GTPases mediate the protein transport through and between these organelles. The ER-localized GTPase, Sar1, facilitates the formation of COPII transport carriers at the ER exit sites (ERES on the ER for the transport of cargo proteins from the ER to the Golgi. The Golgi-localized GTPase, Arf1, controls intra-Golgi, and Golgi-to-ER transport of cargo proteins by the formation of COPI carriers. Rab GTPases localized at the Golgi, which are responsible for fusion of membranes, are thought to establish the identities of compartments. Recent evidence suggests that these small GTPases regulate not only discrete sites for generation/fusion of transport carriers, but also membrane dynamics of the organelles where they locate to ensure the integrity of transport. Here we summarize the current understandings about the membrane traffic between these organelles and highlight the cutting-edge advances from super-resolution live imaging of budding yeast, Saccharomyces cerevisiae.

Non-synaptic signaling from cerebellar climbing fibers modulates Golgi cell activity.

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Nietz, Angela K; Vaden, Jada H; Coddington, Luke T; Overstreet-Wadiche, Linda; Wadiche, Jacques I

2017-10-13

Golgi cells are the principal inhibitory neurons at the input stage of the cerebellum, providing feedforward and feedback inhibition through mossy fiber and parallel fiber synapses. In vivo studies have shown that Golgi cell activity is regulated by climbing fiber stimulation, yet there is little functional or anatomical evidence for synapses between climbing fibers and Golgi cells. Here, we show that glutamate released from climbing fibers activates ionotropic and metabotropic receptors on Golgi cells through spillover-mediated transmission. The interplay of excitatory and inhibitory conductances provides flexible control over Golgi cell spiking, allowing either excitation or a biphasic sequence of excitation and inhibition following single climbing fiber stimulation. Together with prior studies of spillover transmission to molecular layer interneurons, these results reveal that climbing fibers exert control over inhibition at both the input and output layers of the cerebellar cortex.

The Arf-GDP-regulated recruitment of GBF1 to Golgi membranes requires domains HDS1 and HDS2 and a Golgi-localized protein receptor.

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Quilty, Douglas; Chan, Calvin J; Yurkiw, Katherine; Bain, Alexandra; Babolmorad, Ghazal; Melançon, Paul

2018-04-19

We previously proposed a novel mechanism by which the enzyme Golgi-specific Brefeldin A resistance factor 1 (GBF1) is recruited to the membranes of the cis -Golgi, based on in vivo experiments. Here, we extended our in vivo analysis on the production of regulatory Arf-GDP and observed that ArfGAP2 and ArfGAP3 do not play a role in GBF1 recruitment. We confirm that Arf-GDP localization is critical, as a TGN-localized Arf-GDP mutant protein fails to promote GBF1 recruitment. We also reported the establishment of an in vitro GBF1 recruitment assay that supports the regulation of GBF1 recruitment by Arf-GDP. This in vitro assay yielded further evidence for the requirement of a Golgi-localized protein because heat denaturation or protease treatment of Golgi membranes abrogated GBF1 recruitment. Finally, combined in vivo and in vitro measurements indicated that the recruitment to Golgi membranes via a putative receptor requires only the HDS1 and HDS2 domains in the C-terminal half of GBF1. © 2018. Published by The Company of Biologists Ltd.

Journeys through the Golgi--taking stock in a new era.

Science.gov (United States)

Emr, Scott; Glick, Benjamin S; Linstedt, Adam D; Lippincott-Schwartz, Jennifer; Luini, Alberto; Malhotra, Vivek; Marsh, Brad J; Nakano, Akihiko; Pfeffer, Suzanne R; Rabouille, Catherine; Rothman, James E; Warren, Graham; Wieland, Felix T

2009-11-16

The Golgi apparatus is essential for protein sorting and transport. Many researchers have long been fascinated with the form and function of this organelle. Yet, despite decades of scrutiny, the mechanisms by which proteins are transported across the Golgi remain controversial. At a recent meeting, many prominent Golgi researchers assembled to critically evaluate the core issues in the field. This report presents the outcome of their discussions and highlights the key open questions that will help guide the field into a new era.

OSBP-related protein 11 (ORP11) dimerizes with ORP9 and localizes at the Golgi-late endosome interface

International Nuclear Information System (INIS)

Zhou, You; Li, Shiqian; Maeyraenpaeae, Mikko I.; Zhong, Wenbin; Baeck, Nils; Yan, Daoguang; Olkkonen, Vesa M.

2010-01-01

We characterize here ORP11, a member of the oxysterol-binding protein family. ORP11 is present at highest levels in human ovary, testis, kidney, liver, stomach, brain, and adipose tissue. Immunohistochemistry demonstrates abundant ORP11 in the epithelial cells of kidney tubules, testicular tubules, caecum, and skin. ORP11 in HEK293 cells resides on Golgi complex and LE, co-localizing with GFP-Rab9, TGN46, GFP-Rab7, and a fluorescent medial-trans-Golgi marker. Under electron microscopic observation, cells overexpressing ORP11 displayed lamellar lipid bodies associated with vacuolar structures or the Golgi complex, indicating a disturbance of lipid trafficking. N-terminal fragment of ORP11 (aa 1-292) localized partially to Golgi, but displayed enhanced localization on Rab7- and Rab9-positive LE, while the C-terminal ligand-binding domain (aa 273-747) was cytosolic, demonstrating that the membrane targeting determinants are N-terminal. Yeast two-hybrid screen revealed interaction of ORP11 with the related ORP9. The interacting region was delineated within aa 98-372 of ORP9 and aa 154-292 of ORP11. Overexpressed ORP9 was able to recruit EGFP-ORP11 to membranes, and ORP9 silencing inhibited ORP11 Golgi association. The results identify ORP11 as an OSBP homologue distributing at the Golgi-LE interface and define the ORP9-ORP11 dimer as a functional unit that may act as an intracellular lipid sensor or transporter.

OSBP-related protein 11 (ORP11) dimerizes with ORP9 and localizes at the Golgi-late endosome interface

Energy Technology Data Exchange (ETDEWEB)

Zhou, You [Minerva Foundation Institute for Medical Research, Biomedicum 2U, and National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum 1, FI-00290, Helsinki (Finland); Li, Shiqian [Department of Biology, Jinan University, Guangzhou 510632 (China); Maeyraenpaeae, Mikko I. [Wihuri Research Institute, FI-00140 Helsinki, and the Department of Forensic Medicine, FI-00014 University of Helsinki (Finland); Zhong, Wenbin [Department of Biology, Jinan University, Guangzhou 510632 (China); Baeck, Nils [Institute of Biomedicine/Anatomy, FI-00014 University of Helsinki, Helsinki (Finland); Yan, Daoguang [Department of Biology, Jinan University, Guangzhou 510632 (China); Olkkonen, Vesa M., E-mail: vesa.olkkonen@helsinki.fi [Minerva Foundation Institute for Medical Research, Biomedicum 2U, and National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum 1, FI-00290, Helsinki (Finland); Institute of Biomedicine/Anatomy, FI-00014 University of Helsinki, Helsinki (Finland)

2010-11-15

We characterize here ORP11, a member of the oxysterol-binding protein family. ORP11 is present at highest levels in human ovary, testis, kidney, liver, stomach, brain, and adipose tissue. Immunohistochemistry demonstrates abundant ORP11 in the epithelial cells of kidney tubules, testicular tubules, caecum, and skin. ORP11 in HEK293 cells resides on Golgi complex and LE, co-localizing with GFP-Rab9, TGN46, GFP-Rab7, and a fluorescent medial-trans-Golgi marker. Under electron microscopic observation, cells overexpressing ORP11 displayed lamellar lipid bodies associated with vacuolar structures or the Golgi complex, indicating a disturbance of lipid trafficking. N-terminal fragment of ORP11 (aa 1-292) localized partially to Golgi, but displayed enhanced localization on Rab7- and Rab9-positive LE, while the C-terminal ligand-binding domain (aa 273-747) was cytosolic, demonstrating that the membrane targeting determinants are N-terminal. Yeast two-hybrid screen revealed interaction of ORP11 with the related ORP9. The interacting region was delineated within aa 98-372 of ORP9 and aa 154-292 of ORP11. Overexpressed ORP9 was able to recruit EGFP-ORP11 to membranes, and ORP9 silencing inhibited ORP11 Golgi association. The results identify ORP11 as an OSBP homologue distributing at the Golgi-LE interface and define the ORP9-ORP11 dimer as a functional unit that may act as an intracellular lipid sensor or transporter.

Phospholipase D is involved in the formation of Golgi associated clathrin coated vesicles in human parotid duct cells.

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Lorena Brito de Souza

Full Text Available Phospholipase D (PLD has been implicated in many cellular functions, such as vesicle trafficking, exocytosis, differentiation, and proliferation. The aim of this study was to characterize the role of PLD in HSY cells, a human cell line originating from the intercalated duct of the parotid gland. As the function and intracellular localization of PLD varies according to cell type, initially, the intracellular localization of PLD1 and PLD2 was determined. By immunofluorescence, PLD1 and PLD2 both showed a punctate cytoplasmic distribution with extensive co-localization with TGN-46. PLD1 was also found in the nucleus, while PLD2 was associated with the plasma membrane. Treatment of cells with the primary alcohol 1-butanol inhibits the hydrolysis of phosphatidylcoline by PLD thereby suppressing phosphatidic acid (PA production. In untreated HSY cells, there was only a slight co-localization of PLD with the clathrin coated vesicles. When HSY cells were incubated with 1-butanol the total number of clathrin coated vesicles increased, especially in the juxtanuclear region and the co-localization of PLD with the clathrin coated vesicles was augmented. Transmission electron microscopy confirmed that the number of Golgi-associated coated vesicles was greater. Treatment with 1-butanol also affected the Golgi apparatus, increasing the volume of the Golgi saccules. The decrease in PA levels after treatment with 1-butanol likewise resulted in an accumulation of enlarged lysosomes in the perinuclear region. Therefore, in HSY cells PLD appears to be involved in the formation of Golgi associated clathrin coated vesicles as well as in the structural maintenance of the Golgi apparatus.

Induced oligomerization targets Golgi proteins for degradation in lysosomes.

Science.gov (United States)

Tewari, Ritika; Bachert, Collin; Linstedt, Adam D

2015-12-01

Manganese protects cells against forms of Shiga toxin by down-regulating the cycling Golgi protein GPP130. Down-regulation occurs when Mn binding causes GPP130 to oligomerize and traffic to lysosomes. To determine how GPP130 is redirected to lysosomes, we tested the role of GGA1 and clathrin, which mediate sorting in the canonical Golgi-to-lysosome pathway. GPP130 oligomerization was induced using either Mn or a self-interacting version of the FKBP domain. Inhibition of GGA1 or clathrin specifically blocked GPP130 redistribution, suggesting recognition of the aggregated GPP130 by the GGA1/clathrin-sorting complex. Unexpectedly, however, GPP130's cytoplasmic domain was not required, and redistribution also occurred after removal of GPP130 sequences needed for its normal cycling. Therefore, to test whether aggregate recognition might be a general phenomenon rather than one involving a specific GPP130 determinant, we induced homo-oligomerization of two unrelated Golgi-targeted constructs using the FKBP strategy. These were targeted to the cis- and trans-Golgi, respectively, using domains from mannosidase-1 and galactosyltransferase. Significantly, upon oligomerization, each redistributed to peripheral punctae and was degraded. This occurred in the absence of detectable UPR activation. These findings suggest the unexpected presence of quality control in the Golgi that recognizes aggregated Golgi proteins and targets them for degradation in lysosomes. © 2015 Tewari et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Retention in the Golgi apparatus and expression on the cell surface of Cfr/Esl-1/Glg-1/MG-160 are regulated by two distinct mechanisms.

Science.gov (United States)

Miyaoka, Yuichiro; Kato, Hidenori; Ebato, Kazuki; Saito, Shigeru; Miyata, Naoko; Imamura, Toru; Miyajima, Atsushi

2011-11-15

Cfr (cysteine-rich fibroblast growth factor receptor) is an Fgf (fibroblast growth factor)-binding protein without a tyrosine kinase. We have shown previously that Cfr is involved in Fgf18 signalling via Fgf receptor 3c. However, as Cfr is also known as Glg (Golgi apparatus protein)-1 or MG-160 and occurs in the Golgi apparatus, it remains unknown how the distribution of Cfr is regulated. In the present study, we performed a mutagenic analysis of Cfr to show that two distinct regions contribute to its distribution and stability. First, the C-terminal region retains Cfr in the Golgi apparatus. Secondly, the Cfr repeats in the extracellular juxtamembrane region destabilizes Cfr passed through the Golgi apparatus. This destabilization does not depend on the cleavage and secretion of the extracellular domain of Cfr. Furthermore, we found that Cfr with a GPI (glycosylphosphatidylinositol) anchor was predominantly expressed on the cell surface in Ba/F3 cells and affected Fgf18 signalling in a similar manner to the full-length Cfr, indicating that the interaction of Cfr with Fgfs on the cell surface is important for its function in Fgf signalling. These results suggest that the expression of Cfr in the Golgi apparatus and on the plasma membrane is finely tuned through two distinct mechanisms for exhibiting different functions.

Disruption of spatial organization and interjoint coordination in Parkinson's disease, progressive supranuclear palsy, and multiple system atrophy.

Science.gov (United States)

Leiguarda, R; Merello, M; Balej, J; Starkstein, S; Nogues, M; Marsden, C D

2000-07-01

Patients with basal ganglia diseases may exhibit ideomotor apraxia. To define the nature of the impairment of the action production system, we studied a repetitive gesture of slicing bread by three-dimensional computergraphic analysis in eight nondemented patients with Parkinson's disease in the "on" state, five with progressive supranuclear palsy and four with multiple system atrophy. Two patients with Parkinson's disease and two with progressive supranuclear palsy showed ideomotor apraxia for transitive movements on standard testing. A Selspott II system was used for kinematic analysis of wrist trajectories and angular motions of the shoulder and elbow joints. Patients with Parkinson's disease, progressive supranuclear palsy, and even some with multiple system atrophy exhibited kinematic deficits in the spatial precision of movement and velocity-curvature relationships; in addition, they failed to maintain proper angle/angle relationships and to apportion their relative joint amplitudes normally. Spatial disruption of wrist trajectories was more severe in patients with ideomotor apraxia. We posit that the basal ganglia are part of the parallel parieto-frontal circuits devoted to sensorimotor integration for object-oriented behavior. The severity and characteristics of spatial abnormalities of a transitive movement would therefore depend on the location and distribution of the pathologic process within these circuits.

Golgi organization and the apical extension of fungal hyphae: an essential relationship.

Science.gov (United States)

Harris, Steven D

2013-07-01

The Golgi apparatus performs crucial functions in the sorting and processing of proteins destined for secretion from eukaryotic cells. In filamentous fungi, organization of the Golgi apparatus reflects the unique challenges brought about by the highly polarized nature of hyphal growth. Recent results show that Golgi compartments are spatially segregated within hyphal tip cells in a manner that depends upon the integrity of the cytoskeleton. Moreover, loss of normal Golgi organization stops polarized hyphal extension and triggers de-polarization of the hyphal tip. These results emphasize the point that a spatially organized and dynamic Golgi apparatus represents an adaptation that is as important for hyphal extension as is the presence of a Spitzenkörper. In addition, they also identify regulatory mechanisms that could enable controlled de-polarization of hyphae during development or infection-related morphogenesis. © 2013 John Wiley & Sons Ltd.

Synthesis of cell wall xylans and glucans by golgi membranes

International Nuclear Information System (INIS)

Gibeaut, D.M.; Carpita, N.C.

1989-01-01

We investigated the biosynthesis of mixed-linkage β-D-glucan and glucuronoarabinoxylans which make up the hemicellulosic matrix of the primary cell walls of maize and other cereal grasses. The Golgi apparatus was enriched from plasma membrane and other organelles by flotation density gradient centrifugation. Glucan synthase I and II, which are established markers for Golgi and plasma membrane, respectively, displayed considerable overlap in conventional separations with sucrose density gradients. Flotation gradients improved separation of the membranes substantially, but the different synthases themselves also incorporated radioactivity from either 10 μM or 1 mM UDP-[ 14 C]-glucose into polymer. Relative incorporation of radioactivity into polymers from UDP-[ 14 C]-xylose by the various membrane fractions was nearly identical to relative IDPase activities, indicating that combined xylosyl transferase-xylan synthase represents a new, unequivocal marker for the Golgi apparatus. We also have developed techniques of gas-liquid chromatography and radiogas proportional counting to achieve capillary quality separation of partially methylated alditol acetates with simultaneous determination of radioactivity in the derivatives. Digestion of polymeric products by specific endo-glycanohydrolases to diagnostic oligosaccharides also reveal specific kinds of polysaccharides synthesized by the Golgi membranes. A combination of these techniques provides unequivocal determination of the linkage structure of specific polymers synthesized by the purified Golgi apparatus

Golgi-type I and Golgi-type II neurons in the ventral anterior thalamic nucleus of the adult human: morphological features and quantitative analysis.

Science.gov (United States)

Al-Hussain Bani Hani, Saleh M; El-Dwairi, Qasim A; Bataineh, Ziad M; Al-Haidari, Mohammad S; Al-Alami, Jamil

2008-05-01

The morphological and quantitative features of neurons in the adult human ventral anterior thalamic nucleus were studied in Golgi preparations. Two neuronal types were found and their quantitative features were studied. Golgi-type I neurons were medium to large cells with dense dendritic trees and dendritic protrusions and short hair-like appendages. They have somatic mean diameter of 30.8 microm (+/-9.4, n = 85). They have an average 100.3 dendritic branches, 48.97 dendritic branching points, and 58.85 dendritic tips. The mean diameters of their primary, secondary, and tertiary dendrites were 3.1 microm (+/-1, n = 80), 1.85 microm (+/-0.8, n = 145), and 1.5 microm (+/-0.4, n = 160), respectively. Golgi-type II neurons were small to medium cells with few sparsely branching dendrites and dendritic stalked appendages with or without terminal swellings. They have somatic mean diameters of 22.2 microm (+/-5.8, n = 120). They have an average 33.76 dendritic branches, 16.49 dendritic branching points, and 21.97 dendritic tips. The mean diameters of their primary, secondary, and tertiary dendrites were 1.6 microm (+/-0.86, n = 70), 1.15 microm (+/-0.55, n = 118), and 1 microm (+/-0.70, n = 95), respectively. These quantitative data may form the basis for further quantitative studies involving aging or some degenerative diseases that may affect cell bodies and/or dendritic trees of the Golgi-type I and/or Golgi-type II thalamic neurons.

Proteomic characterization of golgi membranes enriched from Arabidopsis suspension cell cultures

DEFF Research Database (Denmark)

Hansen, Sara Fasmer; Ebert, Berit; Rautengarten, Carsten

2016-01-01

The plant Golgi apparatus has a central role in the secretory pathway and is the principal site within the cell for the assembly and processing of macromolecules. The stacked membrane structure of the Golgi apparatus along with its interactions with the cytoskeleton and endoplasmic reticulum has...... historically made the isolation and purification of this organelle difficult. Density centrifugation has typically been used to enrich Golgi membranes from plant microsomal preparations, and aside from minor adaptations, the approach is still widely employed. Here we outline the enrichment of Golgi membranes...... from an Arabidopsis cell suspension culture that can be used to investigate the proteome of this organelle. We also provide a useful workflow for the examination of proteomic data as the result of multiple analyses. Finally, we highlight a simple technique to validate the subcellular localization...

Apparent diffusion coefficient measurements in progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Ohshita, T.; Oka, M.; Imon, Y.; Yamaguchi, S.; Mimori, Y.; Nakamura, S. [Hiroshima Univ. (Japan). School of Medicine

2000-09-01

We measured the apparent diffusion coefficient (ADC), using diffusion-weighted imaging (DWI) and signal intensity on T2-weighted MRI in the cerebral white matter of patients with progressive supranuclear palsy (PSP) and age-matched normal subjects. In PSP, ADC in the prefrontal and precentral white matter was significantly higher than in controls. There was no significant difference in signal intensity on T2-weighted images. The ADC did correlate with signal intensity. The distribution of the elevation of ADC may be the consequence of underlying pathological changes, such as neurofibrillary tangles or glial fibrillary tangles in the cortex. Our findings suggest that ADC measurement might be useful for demonstrating subtle neuropathological changes. (orig.)

Golgi enrichment and proteomic analysis of developing Pinus radiata xylem by free-flow electrophoresis.

Directory of Open Access Journals (Sweden)

Harriet T Parsons

Full Text Available Our understanding of the contribution of Golgi proteins to cell wall and wood formation in any woody plant species is limited. Currently, little Golgi proteomics data exists for wood-forming tissues. In this study, we attempted to address this issue by generating and analyzing Golgi-enriched membrane preparations from developing xylem of compression wood from the conifer Pinus radiata. Developing xylem samples from 3-year-old pine trees were harvested for this purpose at a time of active growth and subjected to a combination of density centrifugation followed by free flow electrophoresis, a surface charge separation technique used in the enrichment of Golgi membranes. This combination of techniques was successful in achieving an approximately 200-fold increase in the activity of the Golgi marker galactan synthase and represents a significant improvement for proteomic analyses of the Golgi from conifers. A total of thirty known Golgi proteins were identified by mass spectrometry including glycosyltransferases from gene families involved in glucomannan and glucuronoxylan biosynthesis. The free flow electrophoresis fractions of enriched Golgi were highly abundant in structural proteins (actin and tubulin indicating a role for the cytoskeleton during compression wood formation. The mass spectrometry proteomics data associated with this study have been deposited to the ProteomeXchange with identifier PXD000557.

The asymmetrical structure of Golgi apparatus membranes revealed by in situ atomic force microscope.

Directory of Open Access Journals (Sweden)

Haijiao Xu

Full Text Available The Golgi apparatus has attracted intense attentions due to its fascinating morphology and vital role as the pivot of cellular secretory pathway since its discovery. However, its complex structure at the molecular level remains elusive due to limited approaches. In this study, the structure of Golgi apparatus, including the Golgi stack, cisternal structure, relevant tubules and vesicles, were directly visualized by high-resolution atomic force microscope. We imaged both sides of Golgi apparatus membranes and revealed that the outer leaflet of Golgi membranes is relatively smooth while the inner membrane leaflet is rough and covered by dense proteins. With the treatment of methyl-β-cyclodextrin and Triton X-100, we confirmed the existence of lipid rafts in Golgi apparatus membrane, which are mostly in the size of 20 nm -200 nm and appear irregular in shape. Our results may be of significance to reveal the structure-function relationship of the Golgi complex and pave the way for visualizing the endomembrane system in mammalian cells at the molecular level.

Characterization of the human GARP (Golgi associated retrograde protein) complex

International Nuclear Information System (INIS)

Liewen, Heike; Meinhold-Heerlein, Ivo; Oliveira, Vasco; Schwarzenbacher, Robert; Luo Guorong; Wadle, Andreas; Jung, Martin; Pfreundschuh, Michael; Stenner-Liewen, Frank

2005-01-01

The Golgi associated retrograde protein complex (GARP) or Vps fifty-three (VFT) complex is part of cellular inter-compartmental transport systems. Here we report the identification of the VFT tethering factor complex and its interactions in mammalian cells. Subcellular fractionation shows that human Vps proteins are found in the smooth membrane/Golgi fraction but not in the cytosol. Immunostaining of human Vps proteins displays a vesicular distribution most concentrated at the perinuclear envelope. Co-staining experiments with endosomal markers imply an endosomal origin of these vesicles. Significant accumulation of VFT complex positive endosomes is found in the vicinity of the Trans Golgi Network area. This is in accordance with a putative role in Golgi associated transport processes. In Saccharomyces cerevisiae, GARP is the main effector of the small GTPase Ypt6p and interacts with the SNARE Tlg1p to facilitate membrane fusion. Accordingly, the human homologue of Ypt6p, Rab6, specifically binds hVps52. In human cells, the 'orphan' SNARE Syntaxin 10 is the genuine binding partner of GARP mediated by hVps52. This reveals a previously unknown function of human Syntaxin 10 in membrane docking and fusion events at the Golgi. Taken together, GARP shows significant conservation between various species but diversification and specialization result in important differences in human cells

Computed tomographic findings of progressive supranuclear palsy compared with Parkinson's disease

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Yuki, Nobuhiro; Sato, Shuzo; Yuasa, Tatsuhiko; Ito, Jusuke; Miyatake, Tadashi [Niigata Univ. (Japan). School of Dentistry

1990-10-01

We investigated computed tomographic (CT) films of 4 pathologically documented cases of progressive supranuclear palsy (PSP) in which the clinical presentations were atypical and compared the findings with those of 15 patients with Parkinson's disease (PD). Dilatation of the third ventricle, atrophy of the midbrain tegmentum, and enlargement of the interpeduncular cistern toward the aqueduct were found to be the characteristic findings in PSP. Thus, radiological findings can be useful when the differential diagnosis between PSP and PD is clinically difficult. (author).

Physiological Roles of Plant Post-Golgi Transport Pathways in Membrane Trafficking.

Science.gov (United States)

Uemura, Tomohiro

2016-10-01

Membrane trafficking is the fundamental system through which proteins are sorted to their correct destinations in eukaryotic cells. Key regulators of this system include RAB GTPases and soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs). Interestingly, the numbers of RAB GTPases and SNAREs involved in post-Golgi transport pathways in plant cells are larger than those in animal and yeast cells, suggesting that plants have evolved unique and complex post-Golgi transport pathways. The trans-Golgi network (TGN) is an important organelle that acts as a sorting station in the post-Golgi transport pathways of plant cells. The TGN also functions as the early endosome, which is the first compartment to receive endocytosed proteins. Several endocytosed proteins on the plasma membrane (PM) are initially targeted to the TGN/EE, then recycled back to the PM or transported to the vacuole for degradation. The recycling and degradation of the PM localized proteins is essential for the development and environmental responses in plant. The present review describes the post-Golgi transport pathways that show unique physiological functions in plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Inheritance of the Golgi Apparatus and Cytokinesis Are Controlled by Degradation of GBF1

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Roberto Magliozzi

2018-06-01

Full Text Available Summary: Although much is known about how chromosome segregation is coupled to cell division, how intracellular organelles partition during mitotic division is poorly understood. We report that the phosphorylation-dependent degradation of the ARFGEF GBF1 regulates organelle trafficking during cell division. We show that, in mitosis, GBF1 is phosphorylated on Ser292 and Ser297 by casein kinase-2 allowing recognition by the F-box protein βTrCP. GBF1 interaction with βTrCP recruits GBF1 to the SCFβTrCP ubiquitin ligase complex, triggering its degradation. Phosphorylation and degradation of GBF1 occur along microtubules at the intercellular bridge of telophase cells and are required for Golgi membrane positioning and postmitotic Golgi reformation. Indeed, expression of a non-degradable GBF1 mutant inhibits the transport of the Golgi cluster adjacent to the midbody toward the Golgi twin positioned next to the centrosome and results in defective Golgi reassembly and cytokinesis failure. These findings define a mechanism that controls postmitotic Golgi reassembly and inheritance. : Magliozzi et al. demonstrate that, in mitosis, the ARFGEF GBF1 is targeted for ubiquitin-dependent degradation by casein kinase-2 and the SCFβTrCP ubiquitin ligase and show that GBF1 proteolysis is required for Golgi inheritance and accurate cell division. Keywords: cell division, cytokinesis, mitosis, Golgi apparatus, GBF1, ubiquitin-proteasome system, protein degradation, Cullin-RING ubiquitin ligase

Diffusion tensor analysis of corpus callosum in progressive supranuclear palsy

International Nuclear Information System (INIS)

Ito, Shoichi; Makino, Takahiro; Shirai, Wakako; Hattori, Takamichi

2008-01-01

Progressive supranuclear palsy (PSP) is a neurodegenerative disease featuring parkinsonism, supranuclear ophthalmoplegia, dysphagia, and frontal lobe dysfunction. The corpus callosum which consists of many commissure fibers probably reflects cerebral cortical function. Several previous reports showed atrophy or diffusion abnormalities of anterior corpus callosum in PSP patients, but partitioning method used in these studies was based on data obtained in nonhuman primates. In this study, we performed a diffusion tensor analysis using a new partitioning method for the human corpus callosum. Seven consecutive patients with PSP were compared with 29 age-matched patients with Parkinson's Disease (PD) and 19 age-matched healthy control subjects. All subjects underwent diffusion tensor magnetic resonance imaging, and the corpus callosum was partitioned into five areas on the mid-sagittal plane according to a recently established topography of human corpus callosum (CC1-prefrontal area, CC2-premotor and supplementary motor area, CC3-motor area, CC4-sensory area, CC5-parietal, temporal, and occipital area). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in each area and differences between groups were analyzed. In the PSP group, FA values were significantly decreased in CC1 and CC2, and ADC values were significantly increased in CC1 and CC2. Receiver operating characteristic analysis showed excellent reliability of FA and ADC analyses of CC1 for differentiating PSP from PD. The anterior corpus callosum corresponding to the prefrontal, premotor, and supplementary motor cortices is affected in PSP patients. This analysis can be an additional test for further confirmation of the diagnosis of PSP

Diffusion tensor analysis of corpus callosum in progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Ito, Shoichi; Makino, Takahiro; Shirai, Wakako; Hattori, Takamichi [Department of Neurology, Graduate School of Medicine, Chiba University (Japan)

2008-11-15

Progressive supranuclear palsy (PSP) is a neurodegenerative disease featuring parkinsonism, supranuclear ophthalmoplegia, dysphagia, and frontal lobe dysfunction. The corpus callosum which consists of many commissure fibers probably reflects cerebral cortical function. Several previous reports showed atrophy or diffusion abnormalities of anterior corpus callosum in PSP patients, but partitioning method used in these studies was based on data obtained in nonhuman primates. In this study, we performed a diffusion tensor analysis using a new partitioning method for the human corpus callosum. Seven consecutive patients with PSP were compared with 29 age-matched patients with Parkinson's Disease (PD) and 19 age-matched healthy control subjects. All subjects underwent diffusion tensor magnetic resonance imaging, and the corpus callosum was partitioned into five areas on the mid-sagittal plane according to a recently established topography of human corpus callosum (CC1-prefrontal area, CC2-premotor and supplementary motor area, CC3-motor area, CC4-sensory area, CC5-parietal, temporal, and occipital area). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in each area and differences between groups were analyzed. In the PSP group, FA values were significantly decreased in CC1 and CC2, and ADC values were significantly increased in CC1 and CC2. Receiver operating characteristic analysis showed excellent reliability of FA and ADC analyses of CC1 for differentiating PSP from PD. The anterior corpus callosum corresponding to the prefrontal, premotor, and supplementary motor cortices is affected in PSP patients. This analysis can be an additional test for further confirmation of the diagnosis of PSP.

Mitotic phosphorylation of VCIP135 blocks p97ATPase-mediated Golgi membrane fusion

Energy Technology Data Exchange (ETDEWEB)

Totsukawa, Go; Matsuo, Ayaka; Kubota, Ayano; Taguchi, Yuya; Kondo, Hisao, E-mail: hk228@med.kyushu-u.ac.jp

2013-04-05

Highlights: •VCIP135 is mitotically phosphorylated on Threonine-760 and Serine-767 by Cdc2. •Phosphorylated VCIP135 does not bind to p97ATPase. •The phosphorylation of VCIP135 inhibits p97ATPase-mediated Golgi membrane fusion. -- Abstract: In mammals, the Golgi apparatus is disassembled early mitosis and reassembled at the end of mitosis. For Golgi disassembly, membrane fusion needs to be blocked. Golgi biogenesis requires two distinct p97ATPase-mediated membrane fusion, the p97/p47 and p97/p37 pathways. We previously reported that p47 phosphorylation on Serine-140 and p37 phosphorylation on Serine-56 and Threonine-59 result in mitotic inhibition of the p97/p47 and the p97/p37 pathways, respectively [11,14]. In this study, we show another mechanism of mitotic inhibition of p97-mediated Golgi membrane fusion. We clarified that VCIP135, an essential factor in both p97 membrane fusion pathways, is phosphorylated on Threonine-760 and Serine-767 by Cdc2 at mitosis and that this phosphorylated VCIP135 does not bind to p97. An in vitro Golgi reassembly assay revealed that VCIP135(T760E, S767E), which mimics mitotic phosphorylation, caused no cisternal regrowth. Our results indicate that the phosphorylation of VCIP135 on Threonine-760 and Serine-767 inhibits p97-mediated Golgi membrane fusion at mitosis.

Depletion of the human N-terminal acetyltransferase hNaa30 disrupts Golgi integrity and ARFRP1 localization.

Science.gov (United States)

Starheim, Kristian K; Kalvik, Thomas V; Bjørkøy, Geir; Arnesen, Thomas

2017-04-30

The organization of the Golgi apparatus (GA) is tightly regulated. Golgi stack scattering is observed in cellular processes such as apoptosis and mitosis, and has also been associated with disruption of cellular lipid metabolism and neurodegenerative diseases. Our studies show that depletion of the human N-α-acetyltransferase 30 (hNaa30) induces fragmentation of the Golgi stack in HeLa and CAL-62 cell lines. The GA associated GTPase ADP ribosylation factor related protein 1 (ARFRP1) was previously shown to require N-terminal acetylation for membrane association and based on its N-terminal sequence, it is likely to be a substrate of hNaa30. ARFRP1 is involved in endosome-to- trans -Golgi network (TGN) traffic. We observed that ARFRP1 shifted from a predominantly cis -Golgi and TGN localization to localizing both Golgi and non-Golgi vesicular structures in hNaa30-depleted cells. However, we did not observe loss of membrane association of ARFRP1. We conclude that hNaa30 depletion induces Golgi scattering and induces aberrant ARFRP1 Golgi localization. © 2017 The Author(s).

Study of ethanol-induced Golgi disorganization reveals the potential mechanism of alcohol-impaired N-glycosylation

Science.gov (United States)

Casey, Carol A.; Bhat, Ganapati; Holzapfel, Melissa S.; Petrosyan, Armen

2016-01-01

Background It is known that ethanol (EtOH) and its metabolites have a negative effect on protein glycosylation. The fragmentation of the Golgi apparatus induced by alteration of the structure of largest Golgi matrix protein, giantin, is the major consequence of damaging effects of EtOH-metabolism on the Golgi, however, the link between this and abnormal glycosylation remains unknown. Because previously we have shown that Golgi morphology dictates glycosylation, we examined the effect EtOH administration has on function of Golgi residential enzymes involved in N-glycosylation. Methods HepG2 cells transfected with mouse ADH1 (VA-13 cells) were treated with 35 mM ethanol for 72 h. Male Wistar rats were pair-fed Lieber-DeCarli diets for 5 to 8 weeks. Characterization of Golgi-associated mannosyl (α-1,3-)-glycoprotein beta-1,2-N-acetylglucosaminyltransferase (MGAT1), α-1,2-mannosidase (Man-I) and α-mannosidase II (Man-II) were performed in VA-13 cells and rat hepatocytes followed by 3D Structured Illumination Microscopy (SIM). Results First, we detected that EtOH administration results in the loss of sialylated N-glycans on asialoglycoprotein receptor, however the high mannose-type N-glycans are increased. Further analysis by 3D SIM microscopy revealed that EtOH treatment despite Golgi disorganization does not change cis-Golgi localization for Man-I, but does induce medial-to-cis relocation of MGAT1 and Man-II. Using different approaches, including electron microscopy, we revealed that EtOH treatment results in dysfunction of Arf1 GTPase followed by a deficiency in COPI vesicles at the Golgi. Silencing beta-COP or expression of GDP-bound mutant Arf1(T31N) mimics the EtOH effect on retaining MGAT1 and Man-II at the cis-Golgi, suggesting that (a) EtOH specifically blocks activation of Arf1, and (b) EtOH alters the proper localization of Golgi enzymes through impairment of COPI. Importantly, the level of MGAT1 was reduced, because likely MGAT1, contrary to Man-I and Man

A small-molecule switch for Golgi sulfotransferases.

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de Graffenried, Christopher L; Laughlin, Scott T; Kohler, Jennifer J; Bertozzi, Carolyn R

2004-11-30

The study of glycan function is a major frontier in biology that could benefit from small molecules capable of perturbing carbohydrate structures on cells. The widespread role of sulfotransferases in modulating glycan function makes them prime targets for small-molecule modulators. Here, we report a system for conditional activation of Golgi-resident sulfotransferases using a chemical inducer of dimerization. Our approach capitalizes on two features shared by these enzymes: their requirement of Golgi localization for activity on cellular substrates and the modularity of their catalytic and localization domains. Fusion of these domains to the proteins FRB and FKBP enabled their induced assembly by the natural product rapamycin. We applied this strategy to the GlcNAc-6-sulfotransferases GlcNAc6ST-1 and GlcNAc6ST-2, which collaborate in the sulfation of L-selectin ligands. Both the activity and specificity of the inducible enzymes were indistinguishable from their WT counterparts. We further generated rapamycin-inducible chimeric enzymes comprising the localization domain of a sulfotransferase and the catalytic domain of a glycosyltransferase, demonstrating the generality of the system among other Golgi enzymes. The approach provides a means for studying sulfate-dependent processes in cellular systems and, potentially, in vivo.

Improvement of balance after audio-biofeedback A 6-week intervention study in patients with progressive supranuclear palsy

NARCIS (Netherlands)

Nicolai, S.; Mirelman, A.; Herman, T.; Zijlstra, A.; Mancini, M.; Becker, C.; Lindeman, U.; Berg, D.; Maetzler, W.

Progressive supranuclear palsy (PSP) is a neurodegenerative disease with no sufficient treatment options to date. The most devastating symptom is the loss of balance with consecutive falls Based on the observation that postural control improved in patients with vestibular dysfunction after

Oxysterol-binding Protein Activation at Endoplasmic Reticulum-Golgi Contact Sites Reorganizes Phosphatidylinositol 4-Phosphate Pools*

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Goto, Asako; Charman, Mark; Ridgway, Neale D.

2016-01-01

Oxysterol-binding protein (OSBP) exchanges cholesterol and phosphatidylinositol 4-phosphate (PI-4P) at contact sites between the endoplasmic reticulum (ER) and the trans-Golgi/trans-Golgi network. 25-Hydroxycholesterol (25OH) competitively inhibits this exchange reaction in vitro and causes the constitutive localization of OSBP at the ER/Golgi interface and PI-4P-dependent recruitment of ceramide transfer protein (CERT) for sphingomyelin synthesis. We used PI-4P probes and mass analysis to determine how OSBP controls the availability of PI-4P for this metabolic pathway. Treatment of fibroblasts or Chinese hamster ovary (CHO) cells with 25OH caused a 50–70% reduction in Golgi-associated immunoreactive PI-4P that correlated with Golgi localization of OSBP. In contrast, 25OH caused an OSBP-dependent enrichment in Golgi PI-4P that was detected with a pleckstrin homology domain probe. The cellular mass of phosphatidylinositol monophosphates and Golgi PI-4P measured with an unbiased PI-4P probe (P4M) was unaffected by 25OH and OSBP silencing, indicating that OSBP shifts the distribution of PI-4P upon localization to ER-Golgi contact sites. The PI-4P and sterol binding activities of OSBP were both required for 25OH activation of sphingomyelin synthesis, suggesting that 25OH must be exchanged for PI-4P to be concentrated at contact sites. We propose a model wherein 25OH activation of OSBP promotes the binding and retention of PI-4P at ER-Golgi contact sites. This pool of PI-4P specifically recruits pleckstrin homology domain-containing proteins involved in lipid transfer and metabolism, such as CERT. PMID:26601944

A novel Golgi retention signal RPWS for tumor suppressor UBIAD1.

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Xian Wang

Full Text Available UBIAD1 plays critical roles in physiology including vitamin K and CoQ10 biosynthesis as well as pathophysiology including dyslipimedia-induced SCD (Schnyder's corneal dystrophy, Parkinson's disease, cardiovascular disease and bladder carcinoma. Since the subcellular localization of UBIAD1 varies in different cell types, characterization of the exact subcellular localization of UBIAD1 in specific human disease is vital for understanding its molecular mechanism. As UBIAD1 suppresses bladder carcinoma, we studied its subcellular localization in human bladder carcinoma cell line T24. Since fluorescent images of UBIAD1-EGFP in T24, human prostate cancer cell line PC-3, human embryonic kidney cell line HEK293 and human hepatocyte cell line L02 are similar, these four cell lines were used for present study. Using a combination of fluorescent microscopy and immunohistochemistry, it was found that UBIAD1 localized on the Golgi and endoplasmic reticulum (ER, but not on the plasma membrane, of T24 and HEK293 cells. Using scanning electron microscopy and western blot analysis, we found that UBIAD1 is enriched in the Golgi fraction extracted from the L02 cells, verifying the Golgi localization of UBAID1. Site-directed mutagenesis showed that the RPWS motif, which forms an Arginine finger on the UBIAD1 N terminus, serves as the Golgi retention signal. With both cycloheximide and brefeldin A inhibition assays, it was shown that UBIAD1 may be transported from the endoplasmic reticulum (ER to the Golgi by a COPII-mediated mechanism. Based upon flow cytometry analysis, it is shown that mutation of the RPWS motif reduced the UBIAD1-induced apoptosis of T24 cells, indicating that the proper Golgi localization of UBIAD1 influences its tumor suppressant activity. This study paves the way for further understanding the molecular mechanism of UBIAD1 in human diseases.

Progressive Supranuclear Palsy-like Syndrome After Aortic Aneurysm Repair: A Case Series

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Sirisha Nandipati

2013-12-01

Full Text Available The syndrome of progressive supranuclear palsy‐like syndrome is a rare complication of ascending aortic aneurysm repair. We report two patients with videos and present a table of prior reported cases. To our knowledge there is no previously published video of this syndrome. The suspected mechanism is brainstem injury though neuroimaging is often negative for an associated infarct. We hope our report will increase recognition of this syndrome after aortic surgery, especially in patients with visual complaints.

A role for Sar1 and ARF1 GTPases during Golgi biogenesis in the protozoan parasite Trypanosoma brucei

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Yavuz, Sevil; Warren, Graham

2017-01-01

A single Golgi stack is duplicated and partitioned into two daughter cells during the cell cycle of the protozoan parasite Trypanosoma brucei. The source of components required to generate the new Golgi and the mechanism by which it forms are poorly understood. Using photoactivatable GFP, we show that the existing Golgi supplies components directly to the newly forming Golgi in both intact and semipermeabilized cells. The movement of a putative glycosyltransferase, GntB, requires the Sar1 and ARF1 GTPases in intact cells. In addition, we show that transfer of GntB from the existing Golgi to the new Golgi can be recapitulated in semipermeabilized cells and is sensitive to the GTP analogue GTPγS. We suggest that the existing Golgi is a key source of components required to form the new Golgi and that this process is regulated by small GTPases. PMID:28495798

Nonrandom γ-TuNA-dependent spatial pattern of microtubule nucleation at the Golgi.

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Sanders, Anna A W M; Chang, Kevin; Zhu, Xiaodong; Thoppil, Roslin J; Holmes, William R; Kaverina, Irina

2017-11-07

Noncentrosomal microtubule (MT) nucleation at the Golgi generates MT network asymmetry in motile vertebrate cells. Investigating the Golgi-derived MT (GDMT) distribution, we find that MT asymmetry arises from nonrandom nucleation sites at the Golgi (hotspots). Using computational simulations, we propose two plausible mechanistic models of GDMT nucleation leading to this phenotype. In the "cooperativity" model, formation of a single GDMT promotes further nucleation at the same site. In the "heterogeneous Golgi" model, MT nucleation is dramatically up-regulated at discrete and sparse locations within the Golgi. While MT clustering in hotspots is equally well described by both models, simulating MT length distributions within the cooperativity model fits the data better. Investigating the molecular mechanism underlying hotspot formation, we have found that hotspots are significantly smaller than a Golgi subdomain positive for scaffolding protein AKAP450, which is thought to recruit GDMT nucleation factors. We have further probed potential roles of known GDMT-promoting molecules, including γ-TuRC-mediated nucleation activator (γ-TuNA) domain-containing proteins and MT stabilizer CLASPs. While both γ-TuNA inhibition and lack of CLASPs resulted in drastically decreased GDMT nucleation, computational modeling revealed that only γ-TuNA inhibition suppressed hotspot formation. We conclude that hotspots require γ-TuNA activity, which facilitates clustered GDMT nucleation at distinct Golgi sites. © 2017 Sanders et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

The cerebellar Golgi cell and spatiotemporal organization of granular layer activity

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Egidio eD‘Angelo

2013-05-01

Full Text Available The cerebellar granular layer has been suggested to perform a complex spatiotemporal reconfiguration of incoming mossy fiber signals. Central to this role is the inhibitory action exerted by Golgi cells over granule cells: Golgi cells inhibit granule cells through double feedforward and feedback inhibitory loops and generate a broad lateral inhibition that extends beyond the afferent synaptic field. This characteristic connectivity has recently been investigated in great detail and been correlated with specific functional properties of the neuron. These include theta-frequency pacemaking, network entrainment into coherent oscillations and phase resetting. Important advances have also been made in terms of determining the membrane and synaptic properties of the neuron, and clarifying the mechanisms of activation by input bursts. Moreover, voltage sensitive dye imaging and multi-electrode array recordings, combined with mathematical simulations based on realistic computational models, have improved our understanding of the impact of Golgi cell activity on granular layer circuit computations. These investigations have highlighted the critical role of Golgi cells in: generating dense clusters of granule cell activity organized in center-surround structures, implementing combinatorial operations on multiple mossy fiber inputs, regulating transmission gain and cut-off frequency, controlling spike timing and burst transmission, and determining the sign, intensity and extension of long-term synaptic plasticity at the mossy fiber-granule cell relay. This review considers recent advances in the field, highlighting the functional implications of Golgi cells for granular layer network computation and indicating new challenges for cerebellar research.

Oxysterol-binding Protein Activation at Endoplasmic Reticulum-Golgi Contact Sites Reorganizes Phosphatidylinositol 4-Phosphate Pools.

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Goto, Asako; Charman, Mark; Ridgway, Neale D

2016-01-15

Oxysterol-binding protein (OSBP) exchanges cholesterol and phosphatidylinositol 4-phosphate (PI-4P) at contact sites between the endoplasmic reticulum (ER) and the trans-Golgi/trans-Golgi network. 25-Hydroxycholesterol (25OH) competitively inhibits this exchange reaction in vitro and causes the constitutive localization of OSBP at the ER/Golgi interface and PI-4P-dependent recruitment of ceramide transfer protein (CERT) for sphingomyelin synthesis. We used PI-4P probes and mass analysis to determine how OSBP controls the availability of PI-4P for this metabolic pathway. Treatment of fibroblasts or Chinese hamster ovary (CHO) cells with 25OH caused a 50-70% reduction in Golgi-associated immunoreactive PI-4P that correlated with Golgi localization of OSBP. In contrast, 25OH caused an OSBP-dependent enrichment in Golgi PI-4P that was detected with a pleckstrin homology domain probe. The cellular mass of phosphatidylinositol monophosphates and Golgi PI-4P measured with an unbiased PI-4P probe (P4M) was unaffected by 25OH and OSBP silencing, indicating that OSBP shifts the distribution of PI-4P upon localization to ER-Golgi contact sites. The PI-4P and sterol binding activities of OSBP were both required for 25OH activation of sphingomyelin synthesis, suggesting that 25OH must be exchanged for PI-4P to be concentrated at contact sites. We propose a model wherein 25OH activation of OSBP promotes the binding and retention of PI-4P at ER-Golgi contact sites. This pool of PI-4P specifically recruits pleckstrin homology domain-containing proteins involved in lipid transfer and metabolism, such as CERT. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Conditional deletion of Cadherin 13 perturbs Golgi cells and disrupts social and cognitive behaviors.

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Tantra, M; Guo, L; Kim, J; Zainolabidin, N; Eulenburg, V; Augustine, G J; Chen, A I

2018-02-15

Inhibitory interneurons mediate the gating of synaptic transmission and modulate the activities of neural circuits. Disruption of the function of inhibitory networks in the forebrain is linked to impairment of social and cognitive behaviors, but the involvement of inhibitory interneurons in the cerebellum has not been assessed. We found that Cadherin 13 (Cdh13), a gene implicated in autism spectrum disorder and attention-deficit hyperactivity disorder, is specifically expressed in Golgi cells within the cerebellar cortex. To assess the function of Cdh13 and utilize the manipulation of Cdh13 expression in Golgi cells as an entry point to examine cerebellar-mediated function, we generated mice carrying Cdh13-floxed alleles and conditionally deleted Cdh13 with GlyT2::Cre mice. Loss of Cdh13 results in a decrease in the expression/localization of GAD67 and reduces spontaneous inhibitory postsynaptic current (IPSC) in cerebellar Golgi cells without disrupting spontaneous excitatory postsynaptic current (EPSC). At the behavioral level, loss of Cdh13 in the cerebellum, piriform cortex and endopiriform claustrum have no impact on gross motor coordination or general locomotor behaviors, but leads to deficits in cognitive and social abilities. Mice lacking Cdh13 exhibit reduced cognitive flexibility and loss of preference for contact region concomitant with increased reciprocal social interactions. Together, our findings show that Cdh13 is critical for inhibitory function of Golgi cells, and that GlyT2::Cre-mediated deletion of Cdh13 in non-executive centers of the brain, such as the cerebellum, may contribute to cognitive and social behavioral deficits linked to neurological disorders. © 2018 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.

COPI-mediated retrograde trafficking from the Golgi to the ER regulates EGFR nuclear transport

International Nuclear Information System (INIS)

Wang, Ying-Nai; Wang, Hongmei; Yamaguchi, Hirohito; Lee, Hong-Jen; Lee, Heng-Huan; Hung, Mien-Chie

2010-01-01

Research highlights: → ARF1 activation is involved in the EGFR transport to the ER and the nucleus. → Assembly of γ-COP coatomer mediates EGFR transport to the ER and the nucleus. → Golgi-to-ER retrograde trafficking regulates nuclear transport of EGFR. -- Abstract: Emerging evidence indicates that cell surface receptors, such as the entire epidermal growth factor receptor (EGFR) family, have been shown to localize in the nucleus. A retrograde route from the Golgi to the endoplasmic reticulum (ER) is postulated to be involved in the EGFR trafficking to the nucleus; however, the molecular mechanism in this proposed model remains unexplored. Here, we demonstrate that membrane-embedded vesicular trafficking is involved in the nuclear transport of EGFR. Confocal immunofluorescence reveals that in response to EGF, a portion of EGFR redistributes to the Golgi and the ER, where its NH 2 -terminus resides within the lumen of Golgi/ER and COOH-terminus is exposed to the cytoplasm. Blockage of the Golgi-to-ER retrograde trafficking by brefeldin A or dominant mutants of the small GTPase ADP-ribosylation factor, which both resulted in the disassembly of the coat protein complex I (COPI) coat to the Golgi, inhibit EGFR transport to the ER and the nucleus. We further find that EGF-dependent nuclear transport of EGFR is regulated by retrograde trafficking from the Golgi to the ER involving an association of EGFR with γ-COP, one of the subunits of the COPI coatomer. Our findings experimentally provide a comprehensive pathway that nuclear transport of EGFR is regulated by COPI-mediated vesicular trafficking from the Golgi to the ER, and may serve as a general mechanism in regulating the nuclear transport of other cell surface receptors.

Word-Retrieval in Two Cases of Progressive Supranuclear Palsy

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Jennifer M. Gurd

1997-01-01

Full Text Available In this paper, we describe the detailed neuropsychological investigation of two cases of progressive supranuclear palsy (PSP and demonstrate word-finding difficulties associated with pervasive problems in word-retrieval. The pattern of deficits resembles that seen in Parkinson’s Disease (PD but is more severe, even in very mild PSP, and appears less amenable to cue facilitation. Performance on a variety of word-production tasks is compared, and experimental controls for motor effects on performance are included. The role of stimulus cues in speeded word-finding is addressed experimentally, as are central executive influences on task performance. This combines with functional brain-scan data from single photon emission computed tomography (SPECT which shows reduced frontal perfusion in one of the two cases.

Completed suicide in a case of clinically diagnosed progressive supranuclear palsy.

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Wiener, Jennifer; Moran, Maria T; Haut, Marc W

2015-08-01

We present the clinical history and the cognitive and behavioral presentations of a male patient with suspected progressive supranuclear palsy (PSP) who fatally shot himself in the head. We believe his act of suicide was the consequence of impulsivity, rather than primary depression or mood disturbance. In cases of suspected PSP and other atypical parkinsonisms, health professionals must be aware of neurobehavioral risk factors for suicide attempts and completions to promote patient safety; however, the literature on this topic is sparse. Our case highlights the potentially lethal consequences of impulsivity and other neuropsychiatric symptoms in PSP and related syndromes.

CCDC115 Deficiency Causes a Disorder of Golgi Homeostasis with Abnormal Protein Glycosylation

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Jansen, Jos C.; Cirak, Sebahattin; van Scherpenzeel, Monique; Timal, Sharita; Reunert, Janine; Rust, Stephan; Pérez, Belén; Vicogne, Dorothée; Krawitz, Peter; Wada, Yoshinao; Ashikov, Angel; Pérez-Cerdá, Celia; Medrano, Celia; Arnoldy, Andrea; Hoischen, Alexander; Huijben, Karin; Steenbergen, Gerry; Quelhas, Dulce; Diogo, Luisa; Rymen, Daisy; Jaeken, Jaak; Guffon, Nathalie; Cheillan, David; van den Heuvel, Lambertus P.; Maeda, Yusuke; Kaiser, Olaf; Schara, Ulrike; Gerner, Patrick; van den Boogert, Marjolein A. W.; Holleboom, Adriaan G.; Nassogne, Marie-Cécile; Sokal, Etienne; Salomon, Jody; van den Bogaart, Geert; Drenth, Joost P. H.; Huynen, Martijn A.; Veltman, Joris A.; Wevers, Ron A.; Morava, Eva; Matthijs, Gert; Foulquier, François; Marquardt, Thorsten; Lefeber, Dirk J.

2016-01-01

Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are

Advancing functional dysconnectivity and atrophy in progressive supranuclear palsy

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Jesse A. Brown

2017-01-01

Full Text Available Progressive supranuclear palsy syndrome (PSP-S results from neurodegeneration within a network of brainstem, subcortical, frontal and parietal cortical brain regions. It is unclear how network dysfunction progresses and relates to longitudinal atrophy and clinical decline. In this study, we evaluated patients with PSP-S (n = 12 and healthy control subjects (n = 20 at baseline and 6 months later. Subjects underwent structural MRI and task-free functional MRI (tf-fMRI scans and clinical evaluations at both time points. At baseline, voxel based morphometry (VBM revealed that patients with mild-to-moderate clinical symptoms showed structural atrophy in subcortex and brainstem, prefrontal cortex (PFC; supplementary motor area, paracingulate, dorsal and ventral medial PFC, and parietal cortex (precuneus. Tf-fMRI functional connectivity (FC was examined in a rostral midbrain tegmentum (rMT-anchored intrinsic connectivity network that is compromised in PSP-S. In healthy controls, this network contained a medial parietal module, a prefrontal-paralimbic module, and a subcortical-brainstem module. Baseline FC deficits in PSP-S were most severe in rMT network integrative hubs in the prefrontal-paralimbic and subcortical-brainstem modules. Longitudinally, patients with PSP-S had declining intermodular FC between the subcortical-brainstem and parietal modules, while progressive atrophy was observed in subcortical-brainstem regions (midbrain, pallidum and posterior frontal (perirolandic cortex. This suggested that later-stage subcortical-posterior cortical change may follow an earlier-stage subcortical-anterior cortical disease process. Clinically, patients with more severe baseline impairment showed greater subsequent prefrontal-parietal cortical FC declines and posterior frontal atrophy rates, while patients with more rapid longitudinal clinical decline showed coupled prefrontal-paralimbic FC decline. VBM and FC can augment disease monitoring in PSP

Identification of a Golgi apparatus protein complex important for the asexual erythrocytic cycle of the malaria parasite Plasmodium falciparum.

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Hallée, Stéphanie; Thériault, Catherine; Gagnon, Dominic; Kehrer, Jessica; Frischknecht, Friedrich; Mair, Gunnar R; Richard, Dave

2018-03-26

Compared with other eukaryotic cell types, malaria parasites appear to possess a more rudimentary Golgi apparatus being composed of dispersed, unstacked cis and trans-cisternae. Despite playing a central role in the secretory pathway of the parasite, few Plasmodium Golgi resident proteins have been characterised. We had previously identified a new Golgi resident protein of unknown function, which we had named Golgi Protein 1, and now show that it forms a complex with a previously uncharacterised transmembrane protein (Golgi Protein 2, GP2). The Golgi Protein complex localises to the cis-Golgi throughout the erythrocytic cycle and potentially also during the mosquito stages. Analysis of parasite strains where GP1 expression is conditionally repressed and/or the GP2 gene is inactivated reveals that though the Golgi protein complex is not essential at any stage of the parasite life cycle, it is important for optimal asexual development in the blood stages. © 2018 John Wiley & Sons Ltd.

Quantifying Golgi structure using EM: combining volume-SEM and stereology for higher throughput.

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Ferguson, Sophie; Steyer, Anna M; Mayhew, Terry M; Schwab, Yannick; Lucocq, John Milton

2017-06-01

Investigating organelles such as the Golgi complex depends increasingly on high-throughput quantitative morphological analyses from multiple experimental or genetic conditions. Light microscopy (LM) has been an effective tool for screening but fails to reveal fine details of Golgi structures such as vesicles, tubules and cisternae. Electron microscopy (EM) has sufficient resolution but traditional transmission EM (TEM) methods are slow and inefficient. Newer volume scanning EM (volume-SEM) methods now have the potential to speed up 3D analysis by automated sectioning and imaging. However, they produce large arrays of sections and/or images, which require labour-intensive 3D reconstruction for quantitation on limited cell numbers. Here, we show that the information storage, digital waste and workload involved in using volume-SEM can be reduced substantially using sampling-based stereology. Using the Golgi as an example, we describe how Golgi populations can be sensed quantitatively using single random slices and how accurate quantitative structural data on Golgi organelles of individual cells can be obtained using only 5-10 sections/images taken from a volume-SEM series (thereby sensing population parameters and cell-cell variability). The approach will be useful in techniques such as correlative LM and EM (CLEM) where small samples of cells are treated and where there may be variable responses. For Golgi study, we outline a series of stereological estimators that are suited to these analyses and suggest workflows, which have the potential to enhance the speed and relevance of data acquisition in volume-SEM.

The Golgin GMAP210/TRIP11 anchors IFT20 to the Golgi complex.

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John A Follit

2008-12-01

Full Text Available Eukaryotic cells often use proteins localized to the ciliary membrane to monitor the extracellular environment. The mechanism by which proteins are sorted, specifically to this subdomain of the plasma membrane, is almost completely unknown. Previously, we showed that the IFT20 subunit of the intraflagellar transport particle is localized to the Golgi complex, in addition to the cilium and centrosome, and hypothesized that the Golgi pool of IFT20 plays a role in sorting proteins to the ciliary membrane. Here, we show that IFT20 is anchored to the Golgi complex by the golgin protein GMAP210/Trip11. Mice lacking GMAP210 die at birth with a pleiotropic phenotype that includes growth restriction, ventricular septal defects of the heart, omphalocele, and lung hypoplasia. Cells lacking GMAP210 have normal Golgi structure, but IFT20 is no longer localized to this organelle. GMAP210 is not absolutely required for ciliary assembly, but cilia on GMAP210 mutant cells are shorter than normal and have reduced amounts of the membrane protein polycystin-2 localized to them. This work suggests that GMAP210 and IFT20 function together at the Golgi in the sorting or transport of proteins destined for the ciliary membrane.

Magnetisation transfer measurements of the subcortical grey and white matter in Parkinson's disease with and without dementia and in progressive supranuclear palsy

International Nuclear Information System (INIS)

Hanyu, H.; Asano, T.; Sakurai, H.; Takasaki, M.; Shindo, H.; Abe, K.

2001-01-01

We measured the magnetisation transfer ratio (MTR) in the subcortical grey and white matter of 11 patients with idiopathic Parkinson's disease (PD) without dementia, six with PD with dementia (PDD), six with progressive supranuclear palsy (PSP), and 12 elderly control subjects to assess regional differences in structural brain damage. There were no significant differences in MTR in any region between PD and controls. However, patients with PDD had significantly lower MTR in the subcortical white matter, including the frontal white matter and the genu of the corpus callosum than the controls, whereas PSP had significantly lower MTR in the subcortical grey matter, including the putamen, globus pallidus and thalamus, in addition to the subcortical white matter. This suggests that regional patterns of structural brain damage can be detected using the magnetisation transfer technique. Measurement of MTR in the subcortical grey and white matter may be useful in differential diagnosis. (orig.)

Role of the AP-5 adaptor protein complex in late endosome-to-Golgi retrieval.

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Jennifer Hirst

2018-01-01

Full Text Available The AP-5 adaptor protein complex is presumed to function in membrane traffic, but so far nothing is known about its pathway or its cargo. We have used CRISPR-Cas9 to knock out the AP-5 ζ subunit gene, AP5Z1, in HeLa cells, and then analysed the phenotype by subcellular fractionation profiling and quantitative mass spectrometry. The retromer complex had an altered steady-state distribution in the knockout cells, and several Golgi proteins, including GOLIM4 and GOLM1, were depleted from vesicle-enriched fractions. Immunolocalisation showed that loss of AP-5 led to impaired retrieval of the cation-independent mannose 6-phosphate receptor (CIMPR, GOLIM4, and GOLM1 from endosomes back to the Golgi region. Knocking down the retromer complex exacerbated this phenotype. Both the CIMPR and sortilin interacted with the AP-5-associated protein SPG15 in pull-down assays, and we propose that sortilin may act as a link between Golgi proteins and the AP-5/SPG11/SPG15 complex. Together, our findings suggest that AP-5 functions in a novel sorting step out of late endosomes, acting as a backup pathway for retromer. This provides a mechanistic explanation for why mutations in AP-5/SPG11/SPG15 cause cells to accumulate aberrant endolysosomes, and highlights the role of endosome/lysosome dysfunction in the pathology of hereditary spastic paraplegia and other neurodegenerative disorders.

Golgi coiled-coil proteins contain multiple binding sites for Rab family G proteins

NARCIS (Netherlands)

Sinka, Rita; Gillingham, Alison K.; Kondylis, Vangelis; Munro, Sean

2008-01-01

Vesicles and other carriers destined for the Golgi apparatus must be guided to the correct cisternae. Golgins, long coiled-coil proteins that localize to particular Golgi subdomains via their C termini, are candidate regulators of vesicle sorting. In this study, we report that the GRIP domain

Defects in the COG complex and COG-related trafficking regulators affect neuronal Golgi function.

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Leslie K Climer

2015-10-01

Full Text Available The Conserved Oligomeric Golgi (COG complex is an evolutionarily conserved hetero-octameric protein complex that has been proposed to organize vesicle tethering at the Golgi apparatus. Defects in seven of the eight COG subunits are linked to Congenital Disorders of Glycosylation (CDG-type II, a family of rare diseases involving misregulation of protein glycosylation, alterations in Golgi structure, variations in retrograde trafficking through the Golgi and system-wide clinical pathologies. A troublesome aspect of these diseases are the neurological pathologies such as low IQ, microcephaly and cerebellar atrophy. The essential function of the COG complex is dependent upon interactions with other components of trafficking machinery, such as Rab-GTPases and SNAREs. COG-interacting Rabs and SNAREs have been implicated in neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease. Defects in Golgi maintenance disrupts trafficking and processing of essential proteins, frequently associated with and contributing to compromised neuron function and human disease. Despite the recent advances in molecular neuroscience, the subcellular bases for most neurodegenerative diseases are poorly understood. This article gives an overview of the potential contributions of the COG complex and its Rab and SNARE partners in the pathogenesis of different neurodegenerative disorders.

Transport of soluble proteins through the Golgi occurs by diffusion via continuities across cisternae

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Beznoussenko, Galina V; Parashuraman, Seetharaman; Rizzo, Riccardo; Polishchuk, Roman; Martella, Oliviano; Di Giandomenico, Daniele; Fusella, Aurora; Spaar, Alexander; Sallese, Michele; Capestrano, Maria Grazia; Pavelka, Margit; Vos, Matthijn R; Rikers, Yuri GM; Helms, Volkhard; Mironov, Alexandre A; Luini, Alberto

2014-01-01

The mechanism of transport through the Golgi complex is not completely understood, insofar as no single transport mechanism appears to account for all of the observations. Here, we compare the transport of soluble secretory proteins (albumin and α1-antitrypsin) with that of supramolecular cargoes (e.g., procollagen) that are proposed to traverse the Golgi by compartment progression–maturation. We show that these soluble proteins traverse the Golgi much faster than procollagen while moving through the same stack. Moreover, we present kinetic and morphological observations that indicate that albumin transport occurs by diffusion via intercisternal continuities. These data provide evidence for a transport mechanism that applies to a major class of secretory proteins and indicate the co-existence of multiple intra-Golgi trafficking modes. DOI: http://dx.doi.org/10.7554/eLife.02009.001 PMID:24867214

Proteomic identification of S-nitrosylated Golgi proteins: new insights into endothelial cell regulation by eNOS-derived NO.

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Panjamaporn Sangwung

Full Text Available Endothelial 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.Golgi 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.Seventy-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.Our 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.

PERMANGANATE FIXATION OF THE GOLGI COMPLEX AND OTHER CYTOPLASMIC STRUCTURES OF MAMMALIAN TESTES

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Mollenhauer, Hilton H.; Zebrun, William

1960-01-01

Observations on the fine structure of KMnO4-fixed testes of small mammals (guinea pig, rat, and mouse) reveal certain morphological differences between the spermatogenic and Sertoli cells which have not been demonstrated in the same tissue fixed with OsO4. Aggregates of minute circular profiles, much smaller than the spherical Golgi vesicles, are described in close association with the Golgi complex of developing spermatids. Groups of dense flattened vesicles, individually surrounded by a membrane of different dimensions than that which bounds most of the other cell organelles, appear dispersed within the cytoplasm of some spermatogenic cells. Flattened vesicles of greater density than those belonging to the Golgi complex are reported confined to the inner Golgi zone of developing guinea pig spermatids between the Golgi cisternae and the head cap. The profiles of endoplasmic reticulum within spermatocytes appear shorter, wider, and more tortuous than those of Sertoli cells. Minute cytoplasmic particles approximately 300 A in diameter and of high electron opacity appear randomly disposed in some Sertoli cells. Groups of irregular-shaped ovoid bodies within the developing spermatids are described as resembling portions of cytoplasm from closely adjacent spermatids. Interpretation is presented regarding the fine structure of KMnO4-fixed testes in view of what has already been reported for mammalian testes fixed in OsO4. PMID:13771855

Oxysterol-binding Protein Activation at Endoplasmic Reticulum-Golgi Contact Sites Reorganizes Phosphatidylinositol 4-Phosphate Pools*

OpenAIRE

Goto, Asako; Charman, Mark; Ridgway, Neale D.

2015-01-01

Oxysterol-binding protein (OSBP) exchanges cholesterol and phosphatidylinositol 4-phosphate (PI-4P) at contact sites between the endoplasmic reticulum (ER) and the trans-Golgi/trans-Golgi network. 25-Hydroxycholesterol (25OH) competitively inhibits this exchange reaction in vitro and causes the constitutive localization of OSBP at the ER/Golgi interface and PI-4P-dependent recruitment of ceramide transfer protein (CERT) for sphingomyelin synthesis. We used PI-4P probes and mass analysis to de...

Characterization of the sterol and phosphatidylinositol 4-phosphate binding properties of Golgi-associated OSBP-related protein 9 (ORP9.

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Xinwei Liu

Full Text Available Oxysterol binding protein (OSBP and OSBP-related proteins (ORPS have a conserved lipid-binding fold that accommodates cholesterol, oxysterols and/or phospholipids. The diversity of OSBP/ORPs and their potential ligands has complicated the analysis of transfer and signalling properties of this mammalian gene family. In this study we explored the use of the fluorescent sterol cholestatrienol (CTL to measure sterol binding by ORP9 and competition by other putative ligands. Relative to cholesterol, CTL and dehydroergosterol (DHE were poor ligands for OSBP. In contrast, both long (ORP9L and short (ORP9S variants of ORP9 rapidly extracted CTL, and to a lesser extent DHE, from liposomes. ORP9L and ORP9S also extracted [32P]phosphatidylinositol 4-phosphate (PI-4P from liposomes, which was inhibited by mutating two conserved histidine residues (HH488,489AA at the entrance to the binding pocket but not by a mutation in the lid region that inhibited cholesterol binding. Results of direct binding and competition assays showed that phosphatidylserine was poorly extracted from liposomes by ORP9 compared to CTL and PI-4P. ORP9L and PI-4P did not co-localize in the trans-Golgi/TGN of HeLa cells, and siRNA silencing of ORP9L expression did not affect PI-4P distribution in the Golgi apparatus. However, transient overexpression of ORP9L or ORP9S in CHO cells, but not the corresponding PI-4P binding mutants, prevented immunostaining of Golgi-associated PI-4P. The apparent sequestration of Golgi PI-4P by ORP9S was identified as a possible mechanism for its growth inhibitory effects. These studies identify ORP9 as a dual sterol/PI-4P binding protein that could regulate PI-4P in the Golgi apparatus.

Characterization of the sterol and phosphatidylinositol 4-phosphate binding properties of Golgi-associated OSBP-related protein 9 (ORP9).

Science.gov (United States)

Liu, Xinwei; Ridgway, Neale D

2014-01-01

Oxysterol binding protein (OSBP) and OSBP-related proteins (ORPS) have a conserved lipid-binding fold that accommodates cholesterol, oxysterols and/or phospholipids. The diversity of OSBP/ORPs and their potential ligands has complicated the analysis of transfer and signalling properties of this mammalian gene family. In this study we explored the use of the fluorescent sterol cholestatrienol (CTL) to measure sterol binding by ORP9 and competition by other putative ligands. Relative to cholesterol, CTL and dehydroergosterol (DHE) were poor ligands for OSBP. In contrast, both long (ORP9L) and short (ORP9S) variants of ORP9 rapidly extracted CTL, and to a lesser extent DHE, from liposomes. ORP9L and ORP9S also extracted [32P]phosphatidylinositol 4-phosphate (PI-4P) from liposomes, which was inhibited by mutating two conserved histidine residues (HH488,489AA) at the entrance to the binding pocket but not by a mutation in the lid region that inhibited cholesterol binding. Results of direct binding and competition assays showed that phosphatidylserine was poorly extracted from liposomes by ORP9 compared to CTL and PI-4P. ORP9L and PI-4P did not co-localize in the trans-Golgi/TGN of HeLa cells, and siRNA silencing of ORP9L expression did not affect PI-4P distribution in the Golgi apparatus. However, transient overexpression of ORP9L or ORP9S in CHO cells, but not the corresponding PI-4P binding mutants, prevented immunostaining of Golgi-associated PI-4P. The apparent sequestration of Golgi PI-4P by ORP9S was identified as a possible mechanism for its growth inhibitory effects. These studies identify ORP9 as a dual sterol/PI-4P binding protein that could regulate PI-4P in the Golgi apparatus.

Different decision deficits impair response inhibition in progressive supranuclear palsy and Parkinson's disease.

Science.gov (United States)

Zhang, Jiaxiang; Rittman, Timothy; Nombela, Cristina; Fois, Alessandro; Coyle-Gilchrist, Ian; Barker, Roger A; Hughes, Laura E; Rowe, James B

2016-01-01

Progressive supranuclear palsy and Parkinson's disease have distinct underlying neuropathology, but both diseases affect cognitive function in addition to causing a movement disorder. They impair response inhibition and may lead to impulsivity, which can occur even in the presence of profound akinesia and rigidity. The current study examined the mechanisms of cognitive impairments underlying disinhibition, using horizontal saccadic latencies that obviate the impact of limb slowness on executing response decisions. Nineteen patients with clinically diagnosed progressive supranuclear palsy (Richardson's syndrome), 24 patients with clinically diagnosed Parkinson's disease and 26 healthy control subjects completed a saccadic Go/No-Go task with a head-mounted infrared saccadometer. Participants were cued on each trial to make a pro-saccade to a horizontal target or withhold their responses. Both patient groups had impaired behavioural performance, with more commission errors than controls. Mean saccadic latencies were similar between all three groups. We analysed behavioural responses as a binary decision between Go and No-Go choices. By using Bayesian parameter estimation, we fitted a hierarchical drift-diffusion model to individual participants' single trial data. The model decomposes saccadic latencies into parameters for the decision process: decision boundary, drift rate of accumulation, decision bias, and non-decision time. In a leave-one-out three-way classification analysis, the model parameters provided better discrimination between patients and controls than raw behavioural measures. Furthermore, the model revealed disease-specific deficits in the Go/No-Go decision process. Both patient groups had slower drift rate of accumulation, and shorter non-decision time than controls. But patients with progressive supranuclear palsy were strongly biased towards a pro-saccade decision boundary compared to Parkinson's patients and controls. This indicates a prepotency of

Vibration sensitivity of human muscle spindles and Golgi tendon organs.

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Fallon, James B; Macefield, Vaughan G

2007-07-01

The responses of the various muscle receptors to vibration are more complicated than a naïve categorization into stretch (muscle spindle primary ending), length (muscle spindle secondary endings), and tension (Golgi tendon organs) receptors. To emphasize the similarity of responses to small length changes, we recorded from 58 individual muscle afferents subserving receptors in the ankle or toe dorsiflexors of awake human subjects (32 primary endings, 20 secondary endings, and six Golgi tendon organs). Transverse sinusoidal vibration was applied to the distal tendon of the receptor-bearing muscle, while subjects either remained completely relaxed or maintained a weak isometric contraction of the appropriate muscle. In relaxed muscle, few units responded in a 1:1 manner to vibration, and there was no evidence of a preferred frequency of activation. In active muscle the response profiles of all three receptor types overlapped, with no significant difference in threshold between receptor types. These results emphasize that when intramuscular tension increases during a voluntary contraction, Golgi tendon organs and muscle spindle secondary endings, not just muscle spindle primary endings, can effectively encode small imposed length changes.

Cholesterol depletion of enterocytes. Effect on the Golgi complex and apical membrane trafficking

DEFF Research Database (Denmark)

Hansen, Gert Helge; Niels-Christiansen, L L; Thorsen, Evy

2000-01-01

Intestinal brush border enzymes, including aminopeptidase N and sucrase-isomaltase, are associated with "rafts" (membrane microdomains rich in cholesterol and sphingoglycolipids). To assess the functional role of rafts in the present work, we studied the effect of cholesterol depletion on apical......, the rates of the Golgi-associated complex glycosylation and association with rafts of newly synthesized aminopeptidase N were reduced, and less of the enzyme had reached the brush border membrane after 2 h of labeling. In contrast, the basolateral Na(+)/K(+)-ATPase was neither missorted nor raft......-associated. Our results implicate the Golgi complex/trans-Golgi network in raft formation and suggest a close relationship between this event and apical membrane trafficking....

La técnica de impregnación argéntica de Golgi. Conmemoración del centenario del premio nobel de Medicina (1906 compartido por Camillo Golgi y Santiago Ramón y Cajal

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Orlando Torres-Fernández

2006-12-01

Full Text Available La técnica de Golgi es un sencillo procedimiento histológico que revela la morfología neuronal completa en tres dimensiones. Este método se fundamenta en la formación de depósitos opacos intracelulares de cromato argéntico, producto de la reacción entre el bicromato de potasio y el nitrato de plata (reacción negra. Camillo Golgi, su descubridor, y Santiago Ramón y Cajal, su principal exponente, recibieron el premio nobel de Medicina y Fisiología en 1906 por su contribución al conocimiento de la estructura del sistema nervioso. Gran parte de sus logros se obtuvieron a través de la aplicación del método de impregnación argéntica. Sin embargo, Golgi y Cajal tenían interpretaciones diferentes sobre la estructura del tejido nervioso. Golgi era defensor de la teoría reticular, la cual proponía que el sistema nervioso estaba conformado por una red de células fusionadas a través de los axones a manera de un sincitio. Por el contrario, la doctrina neuronal, defendida por Cajal, sostenía que las neuronas eran células independientes. También se debe a Golgi y su reazione nera el descubrimiento del organelo celular conocido como ‘aparato de Golgi'. La microscopía electrónica confirmó los postulados de la doctrina neuronal, así como la existencia del complejo de Golgi, y contribuyó al resurgimiento de la técnica de impregnación argéntica. Aunque existen métodos modernos de tinción intracelular que revelan imágenes excelentes de la morfología neuronal, la técnica de Golgi se mantiene vigente por ser un método más práctico y menos costoso para el estudio de la morfología normal y patológica de las neuronas.

Foot-and-mouth disease virus-induced RNA polymerase is associated with Golgi apparatus.

OpenAIRE

Polatnick, J; Wool, S H

1985-01-01

Electrophoretic analysis of the Golgi apparatus isolated by differential centrifugation from radiolabeled cells infected with foot-and-mouth disease virus showed about 10 protein bands. The virus-induced RNA polymerase was identified by immunoprecipitation and electron microscope staining procedures. Pulse-chase experiments indicated that the polymerase passed through the Golgi apparatus in less than 1 h.

Stathmin 1/2-triggered microtubule loss mediates Golgi fragmentation in mutant SOD1 motor neurons

NARCIS (Netherlands)

Bellouze, Sarah; Baillat, Gilbert; Buttigieg, Dorothée; de la Grange, Pierre; Rabouille, Catherine; Haase, Georg

2016-01-01

BACKGROUND: Pathological Golgi fragmentation represents a constant pre-clinical feature of many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) but its molecular mechanisms remain hitherto unclear. RESULTS: Here, we show that the severe Golgi fragmentation in transgenic

Inducible Inhibition of Gβγ Reveals Localization-dependent Functions at the Plasma Membrane and Golgi*

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Klayman, Lauren M.; Wedegaertner, Philip B.

2017-01-01

Heterotrimeric G proteins signal at a variety of endomembrane locations, in addition to their canonical function at the cytoplasmic surface of the plasma membrane (PM), where they are activated by cell surface G protein-coupled receptors. Here we focus on βγ signaling at the Golgi, where βγ activates a signaling cascade, ultimately resulting in vesicle fission from the trans-Golgi network (TGN). To develop a novel molecular tool for inhibiting endogenous βγ in a spatial-temporal manner, we take advantage of a lipid association mutant of the widely used βγ inhibitor GRK2ct (GRK2ct-KERE) and the FRB/FKBP heterodimerization system. We show that GRK2ct-KERE cannot inhibit βγ function when expressed in cells, but recruitment to a specific membrane location recovers the ability of GRK2ct-KERE to inhibit βγ signaling. PM-recruited GRK2ct-KERE inhibits lysophosphatidic acid-induced phosphorylation of Akt, whereas Golgi-recruited GRK2ct-KERE inhibits cargo transport from the TGN to the PM. Moreover, we show that Golgi-recruited GRK2ct-KERE inhibits model basolaterally targeted but not apically targeted cargo delivery, for both PM-destined and secretory cargo, providing the first evidence of selectivity in terms of cargo transport regulated by βγ. Last, we show that Golgi fragmentation induced by ilimaquinone and nocodazole is blocked by βγ inhibition, demonstrating that βγ is a key regulator of multiple pathways that impact Golgi morphology. Thus, we have developed a new molecular tool, recruitable GRK2ct-KERE, to modulate βγ signaling at specific subcellular locations, and we demonstrate novel cargo selectivity for βγ regulation of TGN to PM transport and a novel role for βγ in mediating Golgi fragmentation. PMID:27994056

Inducible Inhibition of Gβγ Reveals Localization-dependent Functions at the Plasma Membrane and Golgi.

Science.gov (United States)

Klayman, Lauren M; Wedegaertner, Philip B

2017-02-03

Heterotrimeric G proteins signal at a variety of endomembrane locations, in addition to their canonical function at the cytoplasmic surface of the plasma membrane (PM), where they are activated by cell surface G protein-coupled receptors. Here we focus on βγ signaling at the Golgi, where βγ activates a signaling cascade, ultimately resulting in vesicle fission from the trans-Golgi network (TGN). To develop a novel molecular tool for inhibiting endogenous βγ in a spatial-temporal manner, we take advantage of a lipid association mutant of the widely used βγ inhibitor GRK2ct (GRK2ct-KERE) and the FRB/FKBP heterodimerization system. We show that GRK2ct-KERE cannot inhibit βγ function when expressed in cells, but recruitment to a specific membrane location recovers the ability of GRK2ct-KERE to inhibit βγ signaling. PM-recruited GRK2ct-KERE inhibits lysophosphatidic acid-induced phosphorylation of Akt, whereas Golgi-recruited GRK2ct-KERE inhibits cargo transport from the TGN to the PM. Moreover, we show that Golgi-recruited GRK2ct-KERE inhibits model basolaterally targeted but not apically targeted cargo delivery, for both PM-destined and secretory cargo, providing the first evidence of selectivity in terms of cargo transport regulated by βγ. Last, we show that Golgi fragmentation induced by ilimaquinone and nocodazole is blocked by βγ inhibition, demonstrating that βγ is a key regulator of multiple pathways that impact Golgi morphology. Thus, we have developed a new molecular tool, recruitable GRK2ct-KERE, to modulate βγ signaling at specific subcellular locations, and we demonstrate novel cargo selectivity for βγ regulation of TGN to PM transport and a novel role for βγ in mediating Golgi fragmentation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development

DEFF Research Database (Denmark)

Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng

2016-01-01

assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures......Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport...... accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development....

The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development.

Science.gov (United States)

Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng; Stonebloom, Solomon; Smith-Moritz, Andreia M; Pauly, Markus; Orellana, Ariel; Scheller, Henrik Vibe; Heazlewood, Joshua L

2016-07-06

Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development.

A novel, modernized Golgi-Cox stain optimized for CLARITY cleared tissue.

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Kassem, Mustafa S; Fok, Sandra Y Y; Smith, Kristie L; Kuligowski, Michael; Balleine, Bernard W

2018-01-15

High resolution neuronal information is extraordinarily useful in understanding the brain's functionality. The development of the Golgi-Cox stain allowed observation of the neuron in its entirety with unrivalled detail. Tissue clearing techniques, e.g., CLARITY and CUBIC, provide the potential to observe entire neuronal circuits intact within tissue and without previous restrictions with regard to section thickness. Here we describe an improved Golgi-Cox stain method, optimised for use with CLARITY and CUBIC that can be used in both fresh and fixed tissue. Using this method, we were able to observe neurons in their entirety within a fraction of the time traditionally taken to clear tissue (48h). We were also able to show for the first-time that Golgi stained tissue is fluorescent when visualized using a multi-photon microscope, allowing us to image synaptic spines with a detail previously unachievable. These novel methods provide cheap and easy to use techniques to investigate the morphology of cellular processes in the brain at a new-found depth, speed, utility and detail, without previous restrictions of time, tissue type and section thickness. This is the first application of a Golgi-Cox stain to cleared brain tissue, it is investigated and discussed in detail, describing different methodologies that may be used, a comparison between the different clearing techniques and lastly the novel interaction of these techniques with this ultra-rapid stain. Copyright © 2017 Elsevier B.V. All rights reserved.

The critical role of Golgi cells in regulating spatio-temporal integration and plasticity at the cerebellum input stage

Directory of Open Access Journals (Sweden)

2008-07-01

Full Text Available After the discovery at the end of the 19th century (Golgi, 1883, the Golgi cell was precisely described by S.R. y Cajal (see Cajal, 1987, 1995 and functionally identified as an inhibitory interneuron 50 years later by J.C. Eccles and colleagues (Eccles e al., 1967. Then, its role has been casted by Marr (1969 within the Motor Learning Theory as a codon size regulator of granule cell activity. It was immediately clear that Golgi cells had to play a critical role, since they are the main inhibitory interneuron of the granular layer and control activity of as many as 100 millions granule cells. In vitro, Golgi cells show pacemaking, resonance, phase-reset and rebound-excitation in the theta-frequency band. These properties are likely to impact on their activity in vivo, which shows irregular spontaneous beating modulated by sensory inputs and burst responses to punctuate stimulation followed by a silent pause. Moreover, investigations have given insight into Golgi cells connectivity within the cerebellar network and on their impact on the spatio-temporal organization of activity. It turns out that Golgi cells can control both the temporal dynamics and the spatial distribution of information transmitted through the cerebellar network. Moreover, Golgi cells regulate the induction of long-term synaptic plasticity at the mossy fiber - granule cell synapse. Thus, the concept is emerging that Golgi cells are of critical importance for regulating granular layer network activity bearing important consequences for cerebellar computation as a whole.

Different decision deficits impair response inhibition in progressive supranuclear palsy and Parkinson’s disease

Science.gov (United States)

Rittman, Timothy; Nombela, Cristina; Fois, Alessandro; Coyle-Gilchrist, Ian; Barker, Roger A.; Hughes, Laura E.; Rowe, James B.

2016-01-01

Abstract Progressive supranuclear palsy and Parkinson’s disease have distinct underlying neuropathology, but both diseases affect cognitive function in addition to causing a movement disorder. They impair response inhibition and may lead to impulsivity, which can occur even in the presence of profound akinesia and rigidity. The current study examined the mechanisms of cognitive impairments underlying disinhibition, using horizontal saccadic latencies that obviate the impact of limb slowness on executing response decisions. Nineteen patients with clinically diagnosed progressive supranuclear palsy (Richardson’s syndrome), 24 patients with clinically diagnosed Parkinson’s disease and 26 healthy control subjects completed a saccadic Go/No-Go task with a head-mounted infrared saccadometer. Participants were cued on each trial to make a pro-saccade to a horizontal target or withhold their responses. Both patient groups had impaired behavioural performance, with more commission errors than controls. Mean saccadic latencies were similar between all three groups. We analysed behavioural responses as a binary decision between Go and No-Go choices. By using Bayesian parameter estimation, we fitted a hierarchical drift–diffusion model to individual participants’ single trial data. The model decomposes saccadic latencies into parameters for the decision process: decision boundary, drift rate of accumulation, decision bias, and non-decision time. In a leave-one-out three-way classification analysis, the model parameters provided better discrimination between patients and controls than raw behavioural measures. Furthermore, the model revealed disease-specific deficits in the Go/No-Go decision process. Both patient groups had slower drift rate of accumulation, and shorter non-decision time than controls. But patients with progressive supranuclear palsy were strongly biased towards a pro-saccade decision boundary compared to Parkinson’s patients and controls. This

Localization of three human polypeptide GalNAc-transferases in HeLa cells suggests initiation of O-linked glycosylation throughout the Golgi apparatus

DEFF Research Database (Denmark)

Röttger, S; White, J; Wandall, H H

1998-01-01

O-glycosylation of proteins is initiated by a family of UDP-N-acetylgalactosamine:polypeptide N-acetylgalactos-aminyltransferases (GalNAc-T). In this study, we have localized endogenous and epitope-tagged human GalNAc-T1, -T2 and -T3 to the Golgi apparatus in HeLa cells by subcellular fractionation......, immunofluorescence and immunoelectron microscopy. We show that all three GalNAc-transferases are concentrated about tenfold in Golgi stacks over Golgi associated tubular-vesicular membrane structures. Surprisingly, we find that GalNAc-T1, -T2 and -T3 are present throughout the Golgi stack suggesting that initiation...... of O-glycosylation may not be restricted to the cis Golgi, but occur at multiple sites within the Golgi apparatus. GalNAc-T1 distributes evenly across the Golgi stack whereas GalNAc-T2 and -T3 reside preferentially on the trans side and in the medial part of the Golgi stack, respectively. Moreover, we...

Post-Golgi anterograde transport requires GARP-dependent endosome-to-TGN retrograde transport

Science.gov (United States)

Hirata, Tetsuya; Fujita, Morihisa; Nakamura, Shota; Gotoh, Kazuyoshi; Motooka, Daisuke; Murakami, Yoshiko; Maeda, Yusuke; Kinoshita, Taroh

2015-01-01

The importance of endosome-to–trans-Golgi network (TGN) retrograde transport in the anterograde transport of proteins is unclear. In this study, genome-wide screening of the factors necessary for efficient anterograde protein transport in human haploid cells identified subunits of the Golgi-associated retrograde protein (GARP) complex, a tethering factor involved in endosome-to-TGN transport. Knockout (KO) of each of the four GARP subunits, VPS51–VPS54, in HEK293 cells caused severely defective anterograde transport of both glycosylphosphatidylinositol (GPI)-anchored and transmembrane proteins from the TGN. Overexpression of VAMP4, v-SNARE, in VPS54-KO cells partially restored not only endosome-to-TGN retrograde transport, but also anterograde transport of both GPI-anchored and transmembrane proteins. Further screening for genes whose overexpression normalized the VPS54-KO phenotype identified TMEM87A, encoding an uncharacterized Golgi-resident membrane protein. Overexpression of TMEM87A or its close homologue TMEM87B in VPS54-KO cells partially restored endosome-to-TGN retrograde transport and anterograde transport. Therefore GARP- and VAMP4-dependent endosome-to-TGN retrograde transport is required for recycling of molecules critical for efficient post-Golgi anterograde transport of cell-surface integral membrane proteins. In addition, TMEM87A and TMEM87B are involved in endosome-to-TGN retrograde transport. PMID:26157166

Acyl-CoA-binding protein (ACBP) localizes to the endoplasmic reticulum and Golgi in a ligand-dependent manner in mammalian cells

DEFF Research Database (Denmark)

Hansen, Jesper S; Færgeman, Nils J; Kragelund, Birthe B

2008-01-01

showed that ACBP targeted to the ER (endoplasmic reticulum) and Golgi in a ligand-binding-dependent manner. A variant Y28F/K32A-FACI-50, which is unable to bind acyl-CoA, did no longer show association with the ER and became segregated from the Golgi, as analysed by intensity correlation calculations....... Depletion of fatty acids from cells by addition of FAFBSA (fatty-acid-free BSA) significantly decreased FACI-50 association with the Golgi, whereas fatty acid overloading increased Golgi association, strongly supporting that ACBP associates with the Golgi in a ligand-dependent manner. FRAP (fluorescence...... recovery after photobleaching) showed that the fatty-acid-induced targeting of FACI-50 to the Golgi resulted in a 5-fold reduction in FACI-50 mobility. We suggest that ACBP is targeted to the ER and Golgi in a ligand-binding-dependent manner in living cells and propose that ACBP may be involved...

Direct interaction of the Golgi V-ATPase a-subunit isoform with PI(4)P drives localization of Golgi V-ATPases in yeast.

Science.gov (United States)

Banerjee, Subhrajit; Kane, Patricia M

2017-09-15

Luminal pH and phosphoinositide content are fundamental features of organelle identity. Vacuolar H + -ATPases (V-ATPases) drive organelle acidification in all eukaryotes, and membrane-bound a-subunit isoforms of the V-ATPase are implicated in organelle-specific targeting and regulation. Earlier work demonstrated that the endolysosomal lipid PI(3,5)P 2 activates V-ATPases containing the vacuolar a-subunit isoform in Saccharomyces cerevisiae Here we demonstrate that PI(4)P, the predominant Golgi phosphatidylinositol (PI) species, directly interacts with the cytosolic amino terminal (NT) domain of the yeast Golgi V-ATPase a-isoform Stv1. Lysine-84 of Stv1NT is essential for interaction with PI(4)P in vitro and in vivo, and interaction with PI(4)P is required for efficient localization of Stv1-containing V-ATPases. The cytosolic NT domain of the human V-ATPase a2 isoform specifically interacts with PI(4)P in vitro, consistent with its Golgi localization and function. We propose that NT domains of V o a-subunit isoforms interact specifically with PI lipids in their organelles of residence. These interactions can transmit organelle-specific targeting or regulation information to V-ATPases. © 2017 Banerjee and Kane. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Structural Insights into Arl1-Mediated Targeting of the Arf-GEF BIG1 to the trans-Golgi

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Antonio Galindo

2016-07-01

Full Text Available The GTPase Arf1 is the major regulator of vesicle traffic at both the cis- and trans-Golgi. Arf1 is activated at the cis-Golgi by the guanine nucleotide exchange factor (GEF GBF1 and at the trans-Golgi by the related GEF BIG1 or its paralog, BIG2. The trans-Golgi-specific targeting of BIG1 and BIG2 depends on the Arf-like GTPase Arl1. We find that Arl1 binds to the dimerization and cyclophilin binding (DCB domain in BIG1 and report a crystal structure of human Arl1 bound to this domain. Residues in the DCB domain that bind Arl1 are required for BIG1 to locate to the Golgi in vivo. DCB domain-binding residues in Arl1 have a distinct conformation from those in known Arl1-effector complexes, and this plasticity allows Arl1 to interact with different effectors of unrelated structure. The findings provide structural insight into how Arf1 GEFs, and hence active Arf1, achieve their correct subcellular distribution.

Autometallographic (AMG) technique used for enhancement of the Golgi-Cox staining gives good contrast andhigh resolution of dendrites and spines

DEFF Research Database (Denmark)

Orlowski, Dariusz

Despite the existence of many newer staining methods, Golgi staining still remains the primary method forvisualization of the dendrites and spines. The black deposit in the Golgi-Cox impregnated cells is a Mercuricsulphide, therefore autometallographic (AMG) technique which is used for visualizat...... of dendrites and spines in the rat hippocampus. The describedmethod will be of value for future behavioural-anatomical studies, examining changes in dendrite branching andspine density caused by brain diseases and their subsequent treatment.......Despite the existence of many newer staining methods, Golgi staining still remains the primary method forvisualization of the dendrites and spines. The black deposit in the Golgi-Cox impregnated cells is a Mercuricsulphide, therefore autometallographic (AMG) technique which is used...... for visualization of the metals and metalsulphides/selenides in tissue may be used to enhance the Golgi-Cox staining. We demonstrated accordingly thatuse of AMG enhancement method on the Golgi-Cox staining gives good contrast and high resolution of dendritesand spines. Moreover, this method is cheaper and more...

The Prenylated Rab GTPase Receptor PRA1.F4 Contributes to Protein Exit from the Golgi Apparatus.

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Lee, Myoung Hui; Yoo, Yun-Joo; Kim, Dae Heon; Hanh, Nguyen Hong; Kwon, Yun; Hwang, Inhwan

2017-07-01

Prenylated Rab acceptor1 (PRA1) functions in the recruitment of prenylated Rab proteins to their cognate organelles. Arabidopsis ( Arabidopsis thaliana ) contains a large number of proteins belonging to the AtPRA1 family. However, their physiological roles remain largely unknown. Here, we investigated the physiological role of AtPRA1.F4, a member of the AtPRA1 family. A T-DNA insertion knockdown mutant of AtPRA1.F4 , atpra1.f4 , was smaller in stature than parent plants and possessed shorter roots, whereas transgenic plants overexpressing HA:AtPRA1.F4 showed enhanced development of secondary roots and root hairs. However, both overexpression and knockdown plants exhibited increased sensitivity to high-salt stress, lower vacuolar Na + /K + -ATPase and plasma membrane ATPase activities, lower and higher pH in the vacuole and apoplast, respectively, and highly vesiculated Golgi apparatus. HA:AtPRA1.F4 localized to the Golgi apparatus and assembled into high-molecular-weight complexes. atpra1.f4 plants displayed a defect in vacuolar trafficking, which was complemented by low but not high levels of HA : AtPRA1.F4 Overexpression of HA:AtPRA1.F4 also inhibited protein trafficking at the Golgi apparatus, albeit differentially depending on the final destination or type of protein: trafficking of vacuolar proteins, plasma membrane proteins, and trans-Golgi network (TGN)-localized SYP61 was strongly inhibited; trafficking of TGN-localized SYP51 was slightly inhibited; and trafficking of secretory proteins and TGN-localized SYP41 was negligibly or not significantly inhibited. Based on these results, we propose that Golgi-localized AtPRA1.F4 is involved in the exit of many but not all types of post-Golgi proteins from the Golgi apparatus. Additionally, an appropriate level of AtPRA1.F4 is crucial for its function at the Golgi apparatus. © 2017 American Society of Plant Biologists. All Rights Reserved.

A model for the self-organization of vesicular flux and protein distributions in the Golgi apparatus.

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Iaroslav Ispolatov

Full Text Available The generation of two non-identical membrane compartments via exchange of vesicles is considered to require two types of vesicles specified by distinct cytosolic coats that selectively recruit cargo, and two membrane-bound SNARE pairs that specify fusion and differ in their affinities for each type of vesicles. The mammalian Golgi complex is composed of 6-8 non-identical cisternae that undergo gradual maturation and replacement yet features only two SNARE pairs. We present a model that explains how distinct composition of Golgi cisternae can be generated with two and even a single SNARE pair and one vesicle coat. A decay of active SNARE concentration in aging cisternae provides the seed for a cis[Formula: see text]trans SNARE gradient that generates the predominantly retrograde vesicle flux which further enhances the gradient. This flux in turn yields the observed inhomogeneous steady-state distribution of Golgi enzymes, which compete with each other and with the SNAREs for incorporation into transport vesicles. We show analytically that the steady state SNARE concentration decays exponentially with the cisterna number. Numerical solutions of rate equations reproduce the experimentally observed SNARE gradients, overlapping enzyme peaks in cis, medial and trans and the reported change in vesicle nature across the Golgi: Vesicles originating from younger cisternae mostly contain Golgi enzymes and SNAREs enriched in these cisternae and extensively recycle through the Endoplasmic Reticulum (ER, while the other subpopulation of vesicles contains Golgi proteins prevalent in older cisternae and hardly reaches the ER.

Efficacy of Āyurvedic treatment using Pañcakarma combined with balance exercises for disability and balance in progressive supranuclear palsy

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Jindal, Nitin; Shamkuwar, Manoj K.; Kaur, Jaskirat; Berry, Sadhan

2012-01-01

A 55-year-old female presented at Department of Pañcakarma with diagnosis of progressive supranuclear palsy (PSP). For assessing disability, progressive supranuclear palsy rating scale (PSPRS) was used and balance was assessed by using Tetrax Interactive Balance System (IBS) posturography. Āyurvedic treatment was given along with Pañcakarma and balance exercises for 3 months. As part of Āyurvedic treatment, first Virecana karma was done with classical method and then Mātrā basti, Śirobasti, and other palliative treatment was given for 3 months. Amanatidine was not continued during Virecana karma but started thereafter. On comparison with pre-intervention scores, there was a significant improvement in the patient post-treatment. The features which mainly showed improvement were: Eye movements, spontaneous episodes of laughing, dysphagia, dysarthria, double vision, and neck rigidity. Balance showed significant improvement and there was a remarkable decrease in the postural sway. This case study may present new possibilities for treatment of neurodegenerative diseases by Āyurveda. PMID:23929996

Human Diseases Associated with Form and Function of the Golgi Complex

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Jeremy C. Simpson

2013-09-01

Full Text Available The Golgi complex lies at the heart of the secretory pathway and is responsible for modifying proteins and lipids, as well as sorting newly synthesized molecules to their correct destination. As a consequence of these important roles, any changes in its proteome can negatively affect its function and in turn lead to disease. Recently, a number of proteins have been identified, which when either depleted or mutated, result in diseases that affect various organ systems. Here we describe how these proteins have been linked to the Golgi complex, and specifically how they affect either the morphology, membrane traffic or glycosylation ability of this organelle.

Segregation of sphingolipids and sterols during formation of secretory vesicles at the trans-Golgi network

DEFF Research Database (Denmark)

Klemm, Robin W; Ejsing, Christer S.; Surma, Michal A

2009-01-01

The trans-Golgi network (TGN) is the major sorting station in the secretory pathway of all eukaryotic cells. How the TGN sorts proteins and lipids to generate the enrichment of sphingolipids and sterols at the plasma membrane is poorly understood. To address this fundamental question in membrane...... trafficking, we devised an immunoisolation procedure for specific recovery of post-Golgi secretory vesicles transporting a transmembrane raft protein from the TGN to the cell surface in the yeast Saccharomyces cerevisiae. Using a novel quantitative shotgun lipidomics approach, we could demonstrate that TGN...... than the late Golgi membrane, as measured by C-Laurdan spectrophotometry, strongly suggests that lipid rafts play a role in the TGN-sorting machinery....

Phospho-eNOS Ser-1176 is associated with the nucleoli and the Golgi complex in C6 rat glioma cells.

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Klinz, Franz-Josef; Herberg, Natalie; Arnhold, Stefan; Addicks, Klaus; Bloch, Wilhelm

2007-06-29

Enzymatic activity of endothelial nitric oxide synthase (eNOS) is controlled by posttranslational modifications, protein-protein interactions, and subcellular localization. For example, N-terminal fatty acid modifications target eNOS to the Golgi complex where it becomes phosphorylated. We show here by immunofluorescence analysis that phospho-eNOS Ser-1176 is enriched in the perinuclear region of interphase C6 rat glioma cells. Confocal double immunofluorescence microscopy with the Golgi marker protein 58K revealed that phospho-eNOS Ser-1176 is associated with the Golgi complex. Surprisingly, we observed several spots in the nucleus of C6 cells that were positive for phospho-eNOS Ser-1176. Confocal double immunofluorescence analysis with the nucleolus marker protein fibrillarin revealed that within the nucleus phospho-eNOS Ser-1176 is exclusively associated with the nucleoli. It is known that in mitotic cells nucleoli are lost during prophase and rebuild during telophase. In agreement with this, we find no nucleoli-like distribution of phospho-eNOS Ser-1176 in metaphase and anaphase C6 glioma cells. Our finding that phospho-eNOS Ser-1176 is selectively associated with the nucleoli points to a so far unknown role for eNOS in interphase glioma cells.

Sphingomyelin synthesis in rat liver occurs predominantly at the cis and medial cisternae of the Golgi apparatus

International Nuclear Information System (INIS)

Futerman, A.H.; Stieger, B.; Hubbard, A.L.; Pagano, R.E.

1990-01-01

The intracellular site of sphingomyelin (SM) synthesis was examined in subcellular fractions from rat liver using a radioactive ceramide analog N-([1-14C]hexanoyl)-D-erythro-sphingosine. This lipid readily transferred from a complex with bovine serum albumin to liver fractions without disrupting the membranes, and was metabolized to radioactive SM. To prevent degradation of the newly synthesized SM to ceramide, all experiments were performed in the presence of EDTA to minimize neutral sphingomyelinase activity and at neutral pH to minimize acid sphingomyelinase activity. An intact Golgi apparatus fraction gave an 85-98-fold enrichment of SM synthesis and a 58-83-fold enrichment of galactosyltransferase activity. Controlled trypsin digestion demonstrated that SM synthesis was localized to the lumen of intact Golgi apparatus vesicles. Although small amounts of SM synthesis were detected in plasma membrane and rough microsome fractions, after accounting for contamination by Golgi apparatus membranes, their combined activity contributed less than 13% of the total SM synthesis in rat liver. Subfractions of the Golgi apparatus were obtained and characterized by immunoblotting and biochemical assays using cis/medial (mannosidase II) and trans (sialyltransferase and galactosyltransferase) Golgi apparatus markers. The specific activity of SM synthesis was highest in enriched cis and medial fractions but far lower in a trans fraction. We conclude that SM synthesis in rat liver occurs predominantly in the cis and medial cisternae of the Golgi apparatus and not at the plasma membrane or endoplasmic reticulum as has been previously suggested

Characterization of dopaminergic dysfunction in familial progressive supranuclear palsy: an 18F-dopa PET study

International Nuclear Information System (INIS)

Tai, Y.F.; Ahsan, R.L.; Pavese, N.; Brooks, D.J.; Piccini, P.; Yebenes de, J.G.

2007-01-01

We analyzed 18 F-dopa PET data from 11 members of kindreds with familial progressive supranuclear palsy (PSP) to characterize their cerebral dopaminergic dysfunction. Three clinically-affected PSP patients showed reduced 18 F-dopa uptake in the striatum, orbitofrontal cortex and amygdala. One asymptomatic subject exhibited progressive putamen dopaminergic dysfunction. 60 % of subjects with abnormal 18 F-dopa scans developed PSP subsequently. This is the first in vivo documentation of cortical dopaminergic deficiency in PSP. Reduced striatal 18 F-dopa uptake in susceptible relatives may predict later clinical disease. (author)

A rapid method combining Golgi and Nissl staining to study neuronal morphology and cytoarchitecture.

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Pilati, Nadia; Barker, Matthew; Panteleimonitis, Sofoklis; Donga, Revers; Hamann, Martine

2008-06-01

The Golgi silver impregnation technique gives detailed information on neuronal morphology of the few neurons it labels, whereas the majority remain unstained. In contrast, the Nissl staining technique allows for consistent labeling of the whole neuronal population but gives very limited information on neuronal morphology. Most studies characterizing neuronal cell types in the context of their distribution within the tissue slice tend to use the Golgi silver impregnation technique for neuronal morphology followed by deimpregnation as a prerequisite for showing that neuron's histological location by subsequent Nissl staining. Here, we describe a rapid method combining Golgi silver impregnation with cresyl violet staining that provides a useful and simple approach to combining cellular morphology with cytoarchitecture without the need for deimpregnating the tissue. Our method allowed us to identify neurons of the facial nucleus and the supratrigeminal nucleus, as well as assessing cellular distribution within layers of the dorsal cochlear nucleus. With this method, we also have been able to directly compare morphological characteristics of neuronal somata at the dorsal cochlear nucleus when labeled with cresyl violet with those obtained with the Golgi method, and we found that cresyl violet-labeled cell bodies appear smaller at high cellular densities. Our observation suggests that cresyl violet staining is inadequate to quantify differences in soma sizes.

Golgi bypass: skirting around the heart of classical secretion

NARCIS (Netherlands)

Grieve, A.; Rabouille, C.

2011-01-01

Classical secretion consists of the delivery of transmembrane and soluble proteins to the plasma membrane and the extracellular medium, respectively, and is mediated by the organelles of the secretory pathway, the Endoplasmic Reticulum (ER), the ER exit sites, and the Golgi, as described by the

A catechol oxidase AcPPO from cherimoya (Annona cherimola Mill.) is localized to the Golgi apparatus.

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Olmedo, Patricio; Moreno, Adrián A; Sanhueza, Dayan; Balic, Iván; Silva-Sanzana, Christian; Zepeda, Baltasar; Verdonk, Julian C; Arriagada, César; Meneses, Claudio; Campos-Vargas, Reinaldo

2018-01-01

Cherimoya (Annona cherimola) is an exotic fruit with attractive organoleptic characteristics. However, it is highly perishable and susceptible to postharvest browning. In fresh fruit, browning is primarily caused by the polyphenol oxidase (PPO) enzyme catalyzing the oxidation of o-diphenols to quinones, which polymerize to form brown melanin pigment. There is no consensus in the literature regarding a specific role of PPO, and its subcellular localization in different plant species is mainly described within plastids. The present work determined the subcellular localization of a PPO protein from cherimoya (AcPPO). The obtained results revealed that the AcPPO- green fluorescent protein co-localized with a Golgi apparatus marker, and AcPPO activity was present in Golgi apparatus-enriched fractions. Likewise, transient expression assays revealed that AcPPO remained active in Golgi apparatus-enriched fractions obtained from tobacco leaves. These results suggest a putative function of AcPPO in the Golgi apparatus of cherimoya, providing new perspectives on PPO functionality in the secretory pathway, its effects on cherimoya physiology, and the evolution of this enzyme. Copyright © 2017. Published by Elsevier B.V.

Xyloglucan biosynthesis by Golgi membranes from suspension-cultured sycamore (Acer pseudoplatanus) cells

International Nuclear Information System (INIS)

White, A.R.; Xin, Yi

1990-01-01

Xyloglucan is a major hemicellulose polysaccharide in plant cell walls. Biosynthesis of such cell wall polysaccharides is closely linked to the process of plant cell growth and development. Xyloglucan polysaccharides consist of a β-1,4 glucan backbone synthesized by xyloglucan synthase and sidechains of xylose, galactose, and fucose added by other transferase enzymes. Most plant Golgi and plasma membranes also contain glucan synthases I ampersand II, which make β-1,4 and β-1,3 glucans, respectively. All of these enzymes have very similar activities. Cell walls on suspension-cultured cells from Acer pseudoplatanus (sycamore maple) were enzymatically softened prior to cell disruption by passing through a 30 μm nylon screen. Cell membranes from homogenates were separated by ultracentrifugation on top-loaded or flotation sucrose density gradients. Samples were collected by gradient fractionation and assayed for membrane markers and xyloglucan and glucan synthase activities. Standard marker assays (cyt. c reductase for eR, IDPase ampersand UDPase for Golgi, and eosin 5'-malelmide binding for plasma membrane) showed partial separation of these three membrane types. Golgi and plasma membrane markers overlapped in most gradients. Incorporation of 14 C-labeled sugars from UDP-glucose and UDP-xylose was used to detect xyloglucan synthase, glucan synthases I ampersand II, and xylosyl transferase in Golgi membrane fractions. These activities overlapped, although distinct peaks of xyloglucan synthase and xylosyl transferase were found. Ca ++ had a stimulatory effect on glucan synthases I ampersand II, while Mn ++ had an inhibitory effect on glucan synthase I in the presence of Ca ++ . The similarity of these various synthase activities demonstrates the need for careful structural characterization of newly synthesized polysaccharides

CCDC115 Deficiency Causes a Disorder of Golgi Homeostasis with Abnormal Protein Glycosylation.

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Jansen, Jos C; Cirak, Sebahattin; van Scherpenzeel, Monique; Timal, Sharita; Reunert, Janine; Rust, Stephan; Pérez, Belén; Vicogne, Dorothée; Krawitz, Peter; Wada, Yoshinao; Ashikov, Angel; Pérez-Cerdá, Celia; Medrano, Celia; Arnoldy, Andrea; Hoischen, Alexander; Huijben, Karin; Steenbergen, Gerry; Quelhas, Dulce; Diogo, Luisa; Rymen, Daisy; Jaeken, Jaak; Guffon, Nathalie; Cheillan, David; van den Heuvel, Lambertus P; Maeda, Yusuke; Kaiser, Olaf; Schara, Ulrike; Gerner, Patrick; van den Boogert, Marjolein A W; Holleboom, Adriaan G; Nassogne, Marie-Cécile; Sokal, Etienne; Salomon, Jody; van den Bogaart, Geert; Drenth, Joost P H; Huynen, Martijn A; Veltman, Joris A; Wevers, Ron A; Morava, Eva; Matthijs, Gert; Foulquier, François; Marquardt, Thorsten; Lefeber, Dirk J

2016-02-04

Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are challenging. Exome sequencing in a family with three siblings affected by abnormal Golgi glycosylation revealed a homozygous missense mutation, c.92T>C (p.Leu31Ser), in coiled-coil domain containing 115 (CCDC115), the function of which is unknown. The same mutation was identified in three unrelated families, and in one family it was compound heterozygous in combination with a heterozygous deletion of CCDC115. An additional homozygous missense mutation, c.31G>T (p.Asp11Tyr), was found in a family with two affected siblings. All individuals displayed a storage-disease-like phenotype involving hepatosplenomegaly, which regressed with age, highly elevated bone-derived alkaline phosphatase, elevated aminotransferases, and elevated cholesterol, in combination with abnormal copper metabolism and neurological symptoms. Two individuals died of liver failure, and one individual was successfully treated by liver transplantation. Abnormal N- and mucin type O-glycosylation was found on serum proteins, and reduced metabolic labeling of sialic acids was found in fibroblasts, which was restored after complementation with wild-type CCDC115. PSI-BLAST homology detection revealed reciprocal homology with Vma22p, the yeast V-ATPase assembly factor located in the endoplasmic reticulum (ER). Human CCDC115 mainly localized to the ERGIC and to COPI vesicles, but not to the ER. These data, in combination with the phenotypic spectrum, which is distinct from that associated with defects in V-ATPase core subunits, suggest a more general role for CCDC115 in Golgi trafficking. Our study reveals CCDC115 deficiency as a disorder of Golgi homeostasis that can be readily identified via screening for abnormal

Plasma Screening for Progranulin Mutations in Patients with Progressive Supranuclear Palsy and Corticobasal Syndromes.

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Galimberti, Daniela; Bertram, Kelly; Formica, Alessandra; Fenoglio, Chiara; Cioffi, Sara M G; Arighi, Andrea; Scarpini, Elio; Colosimo, Carlo

2016-05-04

Progranulin gene (GRN) mutations are characterized by heterogeneous presentations. Corticobasal syndrome (CBS) is often associated with GRN mutations, whereas association with progressive supranuclear palsy syndrome (PSPS) is rare. Plasma progranulin levels were evaluated in 34 patients, including 19 with PSPS, 12 with CBS, and 3 with mixed signs, with the purpose to screen for the presence of causal mutations, associated with low levels. We found undetectable levels in a patient with CBS. Sequencing confirmed the presence of the Thr272fs deletion. Progranulin mutation screening is suggested in cases of CBS, even in the absence of positive family history for dementia and/or movement disorders.

Retrograde transport of protein toxins through the Golgi apparatus

DEFF Research Database (Denmark)

Sandvig, Kirsten; Skotland, Tore; van Deurs, Bo

2013-01-01

at the cell surface, and they are endocytosed both by clathrin-dependent and clathrin-independent mechanisms. Sorting to the Golgi and retrograde transport to the endoplasmic reticulum (ER) are common to these toxins, but the exact mechanisms turn out to be toxin and cell-type dependent. In the ER...

The early postnatal pattern of vesicle formation in different regions of the porcien small intestine

DEFF Research Database (Denmark)

Elbrønd, Vibeke Sødring; Weström, B.R.

2007-01-01

applied to visualize cytoplasmatic subcellular components such as fat (Oil red O) and carbohydrates (PAS). Appearance and morphology of the epithelial vesicles were compared. In the proximal region several small supranuclear and a single large subnuclear electron dense, eosinophilic and PAS+ vesicle were...

FTLD-TDP with motor neuron disease, visuospatial impairment and a progressive supranuclear palsy-like syndrome: broadening the clinical phenotype of TDP-43 proteinopathies. A report of three cases

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Holmerová Iva

2011-05-01

Full Text Available Abstract Background Frontotemporal lobar degeneration with ubiquitin and TDP-43 positive neuronal inclusions represents a novel entity (FTLD-TDP that may be associated with motor neuron disease (FTLD-MND; involvement of extrapyramidal and other systems has also been reported. Case presentation We present three cases with similar clinical symptoms, including Parkinsonism, supranuclear gaze palsy, visuospatial impairment and a behavioral variant of frontotemporal dementia, associated with either clinically possible or definite MND. Neuropathological examination revealed hallmarks of FTLD-TDP with major involvement of subcortical and, in particular, mesencephalic structures. These cases differed in onset and progression of clinical manifestations as well as distribution of histopathological changes in the brain and spinal cord. Two cases were sporadic, whereas the third case had a pathological variation in the progranulin gene 102 delC. Conclusions Association of a "progressive supranuclear palsy-like" syndrome with marked visuospatial impairment, motor neuron disease and early behavioral disturbances may represent a clinically distinct phenotype of FTLD-TDP. Our observations further support the concept that TDP-43 proteinopathies represent a spectrum of disorders, where preferential localization of pathogenetic inclusions and neuronal cell loss defines clinical phenotypes ranging from frontotemporal dementia with or without motor neuron disease, to corticobasal syndrome and to a progressive supranuclear palsy-like syndrome.

G-rich, a Drosophila selenoprotein, is a Golgi-resident type III membrane protein

International Nuclear Information System (INIS)

Chen, Chang Lan; Shim, Myoung Sup; Chung, Jiyeol; Yoo, Hyun-Seung; Ha, Ji Min; Kim, Jin Young; Choi, Jinmi; Zang, Shu Liang; Hou, Xiao; Carlson, Bradley A.; Hatfield, Dolph L.; Lee, Byeong Jae

2006-01-01

G-rich is a Drosophila melanogaster selenoprotein, which is a homologue of human and mouse SelK. Subcellular localization analysis using GFP-tagged G-rich showed that G-rich was localized in the Golgi apparatus. The fusion protein was co-localized with the Golgi marker proteins but not with an endoplasmic reticulum (ER) marker protein in Drosophila SL2 cells. Bioinformatic analysis of G-rich suggests that this protein is either type II or type III transmembrane protein. To determine the type of transmembrane protein experimentally, GFP-G-rich in which GFP was tagged at the N-terminus of G-rich, or G-rich-GFP in which GFP was tagged at the C-terminus of G-rich, were expressed in SL2 cells. The tagged proteins were then digested with trypsin, and analyzed by Western blot analysis. The results showed that the C-terminus of the G-rich protein was exposed to the cytoplasm indicating it is a type III microsomal membrane protein. G-rich is First selenoprotein identified in the Golgi apparatus

Restoration of compact Golgi morphology in advanced prostate cancer enhances susceptibility to galectin-1-induced apoptosis by modifying mucin O-glycan synthesis.

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Petrosyan, Armen; Holzapfel, Melissa S; Muirhead, David E; Cheng, Pi-Wan

2014-12-01

Prostate cancer progression is associated with upregulation of sialyl-T antigen produced by β-galactoside α-2,3-sialyltransferase-1 (ST3Gal1) but not with core 2-associated polylactosamine despite expression of core 2 N-acetylglucosaminyltransferase-L (C2GnT-L/GCNT1). This property allows androgen-refractory prostate cancer cells to evade galectin-1 (LGALS1)-induced apoptosis, but the mechanism is not known. We have recently reported that Golgi targeting of glycosyltransferases is mediated by golgins: giantin (GOLGB1) for C2GnT-M (GCNT3) and GM130 (GOLGA2)-GRASP65 (GORASP1) or GM130-giantin for core 1 synthase. Here, we show that for Golgi targeting, C2GnT-L also uses giantin exclusively whereas ST3Gal1 uses either giantin or GM130-GRASP65. In addition, the compact Golgi morphology is detected in both androgen-sensitive prostate cancer and normal prostate cells, but fragmented Golgi and mislocalization of C2GnT-L are found in androgen-refractory cells as well as primary prostate tumors (Gleason grade 2-4). Furthermore, failure of giantin monomers to be phosphorylated and dimerized prevents Golgi from forming compact morphology and C2GnT-L from targeting the Golgi. On the other hand, ST3Gal1 reaches the Golgi by an alternate site, GM130-GRASP65. Interestingly, inhibition or knockdown of non-muscle myosin IIA (MYH9) motor protein frees up Rab6a GTPase to promote phosphorylation of giantin by polo-like kinase 3 (PLK3), which is followed by dimerization of giantin assisted by protein disulfide isomerase A3 (PDIA3), and restoration of compact Golgi morphology and targeting of C2GnT-L. Finally, the Golgi relocation of C2GnT-L in androgen-refractory cells results in their increased susceptibility to galectin-1-induced apoptosis by replacing sialyl-T antigen with polylactosamine. This study demonstrates the importance of Golgi morphology and regulation of glycosylation and provides insight into how the Golgi influences cancer progression and metastasis. ©2014 American

Pathological changes of Golgi complex in hemocytoblasts of spleen of young axolotls after x-irradiation

Energy Technology Data Exchange (ETDEWEB)

Turska, R.

1975-01-01

The data available up to now concerning the structure of Golgi complex in different types of normal and pathologically changed cells are very divergent. Results are reported from detailed studies on changes occurring within the Golgi complex in the spleen of three-month old axolotls after x-ray irradiation with a single dose of 1,200 R and killed by decapitation 15, 30, 60 minutes and 3, 6, and 12 hours after irradiation.

Galacturonomannan and Golgi-derived membrane linked to growth and shaping of biogenic calcite

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Marsh, M. E.; Ridall, A. L.; Azadi, P.; Duke, P. J.

2002-01-01

The coccolithophores are valuable models for the design and synthesis of composite materials, because the cellular machinery controlling the nucleation, growth, and patterning of their calcitic scales (coccoliths) can be examined genetically. The coccoliths are formed within the Golgi complex and are the major CaCO(3) component in limestone sediments-particularly those of the Cretaceous period. In this study, we describe mutants lacking a sulfated galacturonomannan and show that this polysaccharide in conjunction with the Golgi-derived membrane is directly linked to the growth and shaping of coccolith calcite but not to the initial orientated nucleation of the mineral phase.

Golgi apparatus-localized synaptotagmin 2 is required for unconventional secretion in Arabidopsis.

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Haiyan Zhang

Full Text Available BACKGROUND: Most secretory proteins contain signal peptides that direct their sorting to the ER and secreted via the conventional ER/Golgi transport pathway, while some signal-peptide-lacking proteins have been shown to export through ER/Golgi independent secretory pathways. Hygromycin B is an aminoglycoside antibiotic produced by Streptomyces hygroscopicus that is active against both prokaryotic and eukaryotic cells. The hygromycin phosphotransferase (HYG(R can phosphorylate and inactivate the hygromycin B, and has been widely used as a positive selective marker in the construction of transgenic plants. However, the localization and trafficking of HYG(R in plant cells remain unknown. Synaptotagmins (SYTs are involved in controlling vesicle endocytosis and exocytosis as calcium sensors in animal cells, while their functions in plant cells are largely unclear. METHODOLOGY/PRINCIPAL FINDINGS: We found Arabidopsis synaptotagmin SYT2 was localized on the Golgi apparatus by immunofluorescence and immunogold labeling. Surprisingly, co-expression of SYT2 and HYG(R caused hypersensitivity of the transgenic Arabidopsis plants to hygromycin B. HYG(R, which lacks a signal sequence, was present in the cytoplasm as well as in the extracellular space in HYG(R-GFP transgenic Arabidopsis plants and its secretion is not sensitive to brefeldin A treatment, suggesting it is not secreted via the conventional secretory pathway. Furthermore, we found that HYG(R-GFP was truncated at carboxyl terminus of HYG(R shortly after its synthesis, and the cells deficient SYT2 failed to efficiently truncate HYG(R-GFP,resulting in HYG(R-GFP accumulated in prevacuoles/vacuoles, indicating that SYT2 was involved in HYG(R-GFP trafficking and secretion. CONCLUSION/SIGNIFICANCE: These findings reveal for the first time that SYT2 is localized on the Golgi apparatus and regulates HYG(R-GFP secretion via the unconventional protein transport from the cytosol to the extracelluar matrix in

A smart drug: a pH-responsive photothermal ablation agent for Golgi apparatus activated cancer therapy.

Science.gov (United States)

Xue, Fengfeng; Wen, Ying; Wei, Peng; Gao, Yilin; Zhou, Zhiguo; Xiao, Shuzhang; Yi, Tao

2017-06-13

We report a pH-responsive photothermal ablation agent (pH-PTT) based on cyanine dyes for photothermal therapy (PTT). The nanoparticles formed by BSA and pH-PTT preferentially accumulated in the Golgi apparatus of cancer cells compared to normal cells, and thus can be specifically activated by the acidic Golgi apparatus in cancer cells for effective PTT both ex vivo and in vivo.

Golgi bypass for local delivery of axonal proteins, fact or fiction?

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González, Carolina; Cornejo, Víctor Hugo; Couve, Andrés

2018-04-06

Although translation of cytosolic proteins is well described in axons, much less is known about the synthesis, processing and trafficking of transmembrane and secreted proteins. A canonical rough endoplasmic reticulum or a stacked Golgi apparatus has not been detected in axons, generating doubts about the functionality of a local route. However, axons contain mRNAs for membrane and secreted proteins, translation factors, ribosomal components, smooth endoplasmic reticulum and post-endoplasmic reticulum elements that may contribute to local biosynthesis and plasma membrane delivery. Here we consider the evidence supporting a local secretory system in axons. We discuss exocytic elements and examples of autonomous axonal trafficking that impact development and maintenance. We also examine whether unconventional post-endoplasmic reticulum pathways may replace the canonical Golgi apparatus. Copyright © 2018. Published by Elsevier Ltd.

Secretory granule formation and membrane recycling by the trans-Golgi network in adipokinetic cells of Locusta migratoria in relation to flight and rest.

Science.gov (United States)

Diederen, J H; Vullings, H G

1995-03-01

The influence of flight activity on the formation of secretory granules and the concomitant membrane recycling by the trans-Golgi network in the peptidergic neurosecretory adipokinetic cells of Locusta migratoria was investigated by means of ultrastructural morphometric methods. The patterns of labelling of the trans-Golgi network by the exogenous adsorptive endocytotic tracer wheat-germ agglutinin-conjugated horse-radish peroxidase and by the endogenous marker enzyme acid phosphatase were used as parameters and were measured by an automatic image analysis system. The results show that endocytosed fragments of plasma membrane with bound peroxidase label were transported to the trans-Golgi network and used to build new secretory granules. The amounts of peroxidase and especially of acid phosphatase within the trans-Golgi network showed a strong tendency to be smaller in flight-stimulated cells than in non-stimulated cells. The amounts of acid phosphatase in the immature secretory granules originating from the trans-Golgi network were significantly smaller in stimulated cells. The number of immature secretory granules positive for acid phosphatase tended to be higher in stimulated cells. Thus, flight stimulation of adipokinetic cells for 1 h influences the functioning of the trans-Golgi network; this most probably results in a slight enhancement of the production of secretory granules by the trans-Golgi network.

Blocking variant surface glycoprotein synthesis alters endoplasmic reticulum exit sites/Golgi homeostasis in Trypanosoma brucei.

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Ooi, Cher-Pheng; Smith, Terry K; Gluenz, Eva; Wand, Nadina Vasileva; Vaughan, Sue; Rudenko, Gloria

2018-06-01

The predominant secretory cargo of bloodstream form Trypanosoma brucei is variant surface glycoprotein (VSG), comprising ~10% total protein and forming a dense protective layer. Blocking VSG translation using Morpholino oligonucleotides triggered a precise pre-cytokinesis arrest. We investigated the effect of blocking VSG synthesis on the secretory pathway. The number of Golgi decreased, particularly in post-mitotic cells, from 3.5 ± 0.6 to 2.0 ± 0.04 per cell. Similarly, the number of endoplasmic reticulum exit sites (ERES) in post-mitotic cells dropped from 3.9 ± 0.6 to 2.7 ± 0.1 eight hours after blocking VSG synthesis. The secretory pathway was still functional in these stalled cells, as monitored using Cathepsin L. Rates of phospholipid and glycosylphosphatidylinositol-anchor biosynthesis remained relatively unaffected, except for the level of sphingomyelin which increased. However, both endoplasmic reticulum and Golgi morphology became distorted, with the Golgi cisternae becoming significantly dilated, particularly at the trans-face. Membrane accumulation in these structures is possibly caused by reduced budding of nascent vesicles due to the drastic reduction in the total amount of secretory cargo, that is, VSG. These data argue that the total flux of secretory cargo impacts upon the biogenesis and maintenance of secretory structures and organelles in T. brucei, including the ERES and Golgi. © 2018 The Authors. Traffic published by John Wiley & Sons Ltd.

Brain Dopamine Transporter Binding and Glucose Metabolism in Progressive Supranuclear Palsy-Like Creutzfeldt-Jakob Disease

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Eero Rissanen

2014-01-01

Full Text Available Here, we present a patient with Creutzfeldt-Jakob disease (CJD who developed initial symptoms mimicking progressive supranuclear palsy (PSP. Before the development of typical CJD symptoms, functional imaging supported a diagnosis of PSP when [123I]-FP-CIT-SPECT showed a defect in striatal dopamine transporter binding, while [18F]-fluorodeoxyglucose PET showed cortical hypometabolism suggestive of Lewy body dementia. However, the postmortem neuropathological examination was indicative of CJD only, without tau protein or Lewy body findings. This case demonstrates that CJD should be taken into account in rapidly progressing atypical cases of parkinsonism, even when functional imaging supports a diagnosis of a movement disorder.

Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication.

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Anahí Capmany

2010-11-01

Full Text Available Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication.

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Capmany, Anahí; Damiani, María Teresa

2010-11-22

Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

Environmental and occupational risk factors for progressive supranuclear palsy: Case-control study.

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Litvan, Irene; Lees, Peter S J; Cunningham, Christopher R; Rai, Shesh N; Cambon, Alexander C; Standaert, David G; Marras, Connie; Juncos, Jorge; Riley, David; Reich, Stephen; Hall, Deborah; Kluger, Benzi; Bordelon, Yvette; Shprecher, David R

2016-05-01

The cause of progressive supranuclear palsy (PSP) is largely unknown. Based on evidence for impaired mitochondrial activity in PSP, we hypothesized that the disease may be related to exposure to environmental toxins, some of which are mitochondrial inhibitors. This multicenter case-control study included 284 incident PSP cases of 350 cases and 284 age-, sex-, and race-matched controls primarily from the same geographical areas. All subjects were administered standardized interviews to obtain data on demographics, residential history, and lifetime occupational history. An industrial hygienist and a toxicologist unaware of case status assessed occupational histories to estimate past exposure to metals, pesticides, organic solvents, and other chemicals. Cases and controls were similar on demographic factors. In unadjusted analyses, PSP was associated with lower education, lower income, more smoking pack-years, more years of drinking well water, more years living on a farm, more years living 1 mile from an agricultural region, more transportation jobs, and more jobs with exposure to metals in general. However, in adjusted models, only more years of drinking well water was significantly associated with PSP. There was an inverse association with having a college degree. We did not find evidence for a specific causative chemical exposure; higher number of years of drinking well water is a risk factor for PSP. This result remained significant after adjusting for income, smoking, education and occupational exposures. This is the first case-control study to demonstrate PSP is associated with environmental factors. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

H MR spectroscopy in Parkinson's disease and progressive supranuclear palsy : preliminary study

International Nuclear Information System (INIS)

Chang, Kee Hyun; Jeon, Beom Seok; Song, In Chan; Kim, Dong Sung; Min, Kwan Hong; Han, Moon Hee; Kang, Sa Ouk; Min, Byoung Goo; Han, Man Chung

1996-01-01

To determine whether h magnetic resonance spectroscopy (MRS) is useful in differentiating idiopathic Parkinson's disease (IPD) from progressive supranuclear palsy (PSP), based on metabolite ratios. Using a 1.5 T MR Unit, single voxel H MRS using STEAM with a TR of 2000 ms and a TE of 135ms was performed in seven PD and eight PSP patients. Five age-matched volunteers(mean age, 63 years) and another five younger healthy volunteers(mean age, 30 tears) were studied as normal controls. The regions of interest were the putamen and pallidum, with a size of 2X2X2 cm. After measuring the spectral intensities of each metabolite (N-acetylaspartate=NAA, choline=Cho, creatine=Cr and lactate), relative peak height ratios of NAA/Cr, Cho/Cr and NAA/ Cho, and lactate levels among four groups were compared. NAA/ Cho and NAA/ Cr ratios were statistically lower in the PSP group than the IPD group (1.21 ± 0.26 versus 1.45 ± 0.20, and 1.26 ± 0.23 versus 1.38 ± 0.19, respectively : p 0.05). Cho/Cr ratios were not different among four groups. Lactate was not detected in any patients. NAA/Cho and NAA/Cr ratios in the corpus stratum were significantly lower in the PSP group than in the age-matched control and IPD groups. These results suggest that loss of neuron cells in the corpus stratum is more prominent in PSP than in IPD, and that NAA/Cho and NAA/Cr ratios may help in differential diagnosis of IPD and PSP

Vesicular transport of progeny parvovirus particles through ER and Golgi regulates maturation and cytolysis.

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Bär, Séverine; Rommelaere, Jean; Nüesch, Jürg P F

2013-09-01

Progeny particles of non-enveloped lytic parvoviruses were previously shown to be actively transported to the cell periphery through vesicles in a gelsolin-dependent manner. This process involves rearrangement and destruction of actin filaments, while microtubules become protected throughout the infection. Here the focus is on the intracellular egress pathway, as well as its impact on the properties and release of progeny virions. By colocalization with cellular marker proteins and specific modulation of the pathways through over-expression of variant effector genes transduced by recombinant adeno-associated virus vectors, we show that progeny PV particles become engulfed into COPII-vesicles in the endoplasmic reticulum (ER) and are transported through the Golgi to the plasma membrane. Besides known factors like sar1, sec24, rab1, the ERM family proteins, radixin and moesin play (an) essential role(s) in the formation/loading and targeting of virus-containing COPII-vesicles. These proteins also contribute to the transport through ER and Golgi of the well described analogue of cellular proteins, the secreted Gaussia luciferase in absence of virus infection. It is therefore likely that radixin and moesin also serve for a more general function in cellular exocytosis. Finally, parvovirus egress via ER and Golgi appears to be necessary for virions to gain full infectivity through post-assembly modifications (e.g. phosphorylation). While not being absolutely required for cytolysis and progeny virus release, vesicular transport of parvoviruses through ER and Golgi significantly accelerates these processes pointing to a regulatory role of this transport pathway.

Adiponectin release and insulin receptor targeting share trans-Golgi-dependent endosomal trafficking routes

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Maria Rödiger

2018-02-01

Full Text Available Objective: Intracellular vesicle trafficking maintains cellular structures and functions. The assembly of cargo-laden vesicles at the trans-Golgi network is initiated by the ARF family of small GTPases. Here, we demonstrate the role of the trans-Golgi localized monomeric GTPase ARFRP1 in endosomal-mediated vesicle trafficking of mature adipocytes. Methods: Control (Arfrp1flox/flox and inducible fat-specific Arfrp1 knockout (Arfrp1iAT−/− mice were metabolically characterized. In vitro experiments on mature 3T3-L1 cells and primary mouse adipocytes were conducted to validate the impact of ARFRP1 on localization of adiponectin and the insulin receptor. Finally, secretion and transferrin-based uptake and recycling assays were performed with HeLa and HeLa M-C1 cells. Results: We identified the ARFRP1-based sorting machinery to be involved in vesicle trafficking relying on the endosomal compartment for cell surface delivery. Secretion of adiponectin from fat depots was selectively reduced in Arfrp1iAT−/− mice, and Arfrp1-depleted 3T3-L1 adipocytes revealed an accumulation of adiponectin in Rab11-positive endosomes. Plasma adiponectin deficiency of Arfrp1iAT−/− mice resulted in deteriorated hepatic insulin sensitivity, increased gluconeogenesis and elevated fasting blood glucose levels. Additionally, the insulin receptor, undergoing endocytic recycling after ligand binding, was less abundant at the plasma membrane of adipocytes lacking Arfrp1. This had detrimental effects on adipose insulin signaling, followed by insufficient suppression of basal lipolytic activity and impaired adipose tissue expansion. Conclusions: Our findings suggest that adiponectin secretion and insulin receptor surface targeting utilize the same post-Golgi trafficking pathways that are essential for an appropriate systemic insulin sensitivity and glucose homeostasis. Keywords: Adiponectin, ARFRP1, Exocytosis, Insulin receptor, trans-Golgi

Role of myristoylation in membrane attachment and function of G alpha i-3 on Golgi membranes.

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Brand, S H; Holtzman, E J; Scher, D A; Ausiello, D A; Stow, J L

1996-05-01

Heterotrimeric G protein alpha-subunits localized on the cytoplasmic face of Golgi membranes are involved in regulating vesicle trafficking and protein secretion. We investigated the role of myristoylation in attachment of the G alpha i-3 subunit to Golgi membranes. G alpha i-3 was epitope-tagged by insertion of a FLAG sequence at an NH2-terminal site predicted to interfere with myristoylation, and the resulting NT-alpha i-3 construct was stably transfected and expressed in polarized epithelial LLC-PK1 cells. Metabolic labeling confirmed that the translation product of NT-alpha i-3 was not myristoylated. In contrast to endogenous G alpha 1-3, which is tightly bound to Golgi membranes, the unmyristoylated FLAG-tagged NT-alpha i-3 did not attach to membranes; it was localized by immunofluorescence in the cytoplasm of LLC-PK1 cells and was detected only in the cytosol fraction of cell homogenates. Pertussis toxin-dependent ADP-ribosylation was used to test the ability of NT-alpha i-3 to interact with membrane-bound beta gamma-subunits. In both in vitro and in vivo assays, cytosolic NT-alpha i-3 alone was not ADP-ribosylated, although in the presence of membranes it could interact with G beta gamma-subunits to form heterotrimers. The expression of NT-alpha i-3 in LLC-PK1 cells altered the rate of basolateral secretion of sulfated proteoglycans, consistent with the demonstrated function of endogenous G alpha i-3. These data are consistent with a model in which G alpha i-3 utilizes NH2-terminal myristoylation to bind to Golgi membranes and to maximize its interaction with G beta gamma-subunits. Furthermore, our results show that stable attachment of G alpha i-3 to Golgi membranes is not required for it to participate as a regulatory element in vesicle trafficking in the secretory pathway.

Transport According to GARP: Receiving Retrograde Cargo at the Trans-Golgi Network

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Bonifacino, Juan S.; Hierro, Aitor

2010-01-01

Tethering factors are large protein complexes that capture transport vesicles and enable their fusion with acceptor organelles at different stages of the endomembrane system. Recent studies have shed new light on the structure and function of a heterotetrameric tethering factor named Golgi-associated retrograde protein (GARP), which promotes fusion of endosome-derived, retrograde transport carriers to the trans-Golgi network (TGN). X-ray crystallography of the Vps53 and Vps54 subunits of GARP has revealed that this complex is structurally related to other tethering factors such as the exocyst, COG and Dsl1, indicating that they all might work by a similar mechanism. Loss of GARP function compromises the growth, fertility and/or viability of the defective organisms, underscoring the essential nature of GARP-mediated retrograde transport. PMID:21183348

Live-cell imaging of post-golgi transport vesicles in cultured hippocampal neurons

DEFF Research Database (Denmark)

Jensen, Camilla Stampe; Misonou, Hiroaki

2015-01-01

compartments of neurons. In the past two decades, the establishment and advancement of fluorescent protein technology have provided us with opportunities to study how proteins are trafficked in living cells. However, live imaging of trafficking processes in neurons necessitate imaging tools to distinguish...... the several different routes that neurons use for protein trafficking. Here we provide a novel protocol to selectively visualize post-Golgi transport vesicles carrying fluorescent-labeled ion channel proteins in living neurons. Further, we provide a number of analytical tools we developed to quantify...... mechanisms by which post-Golgi vesicles are trafficked in neurons. Our protocol uniquely combines the classic temperature-block with close monitoring of the transient expression of transfected protein tagged with fluorescent proteins, and provides a quick and easy way to study protein trafficking in living...

Multidimensional fractionation is a requirement for quantitation of Golgi-resident glycosylation enzymes from cultured human cells.

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Lin, Chi-Hung; Chik, Jenny H L; Packer, Nicolle H; Molloy, Mark P

2015-02-06

Glycosylation results from the concerted action of glycosylation enzymes in the secretory pathway. In general, gene expression serves as the primary control mechanism, but post-translational fine-tuning of glycosylation enzyme functions is often necessary for efficient synthesis of specific glycan epitopes. While the field of glycomics has rapidly advanced, there lacks routine proteomic methods to measure expression of specific glycosylation enzymes needed to fill the gap between mRNA expression and the glycomic profile in a "reverse genomics" workflow. Toward developing this workflow we enriched Golgi membranes from two human colon cancer cell lines by sucrose density centrifugation and further mass-based fractionation by SDS-PAGE. We then applied mass spectrometry to demonstrate a doubling in the number of Golgi resident proteins identified, compared to the unenriched, low speed centrifuged supernatant of lysed cells. A total of 35 Golgi-resident glycosylation enzymes, of which 23 were glycosyltransferases, were identified making this the largest protein database so far of Golgi resident glycosylation enzymes experimentally identified in cultured human cells. We developed targeted mass spectrometry assays for specific quantitation of many of these glycosylation enzymes. Our results show that alterations in abundance of glycosylation enzymes at the protein level were generally consistent with the resultant glycomic profiles, but not necessarily with the corresponding glycosyltransferase mRNA expression as exemplified by the case of O-glycan core 1 T synthase.

Monocrotaline pyrrole-induced megalocytosis of lung and breast epithelial cells: Disruption of plasma membrane and Golgi dynamics and an enhanced unfolded protein response

International Nuclear Information System (INIS)

Mukhopadhyay, Somshuvra; Shah, Mehul; Patel, Kirit; Sehgal, Pravin B.

2006-01-01

The pyrrolizidine alkaloid monocrotaline (MCT) initiates pulmonary hypertension by inducing a 'megalocytosis' phenotype in target pulmonary arterial endothelial, smooth muscle and Type II alveolar epithelial cells. In cultured endothelial cells, a single exposure to the pyrrolic derivative of monocrotaline (MCTP) results in large cells with enlarged endoplasmic reticulum (ER) and Golgi and increased vacuoles. However, these cells fail to enter mitosis. Largely based upon data from endothelial cells, we proposed earlier that a disruption of the trafficking and mitosis-sensor functions of the Golgi (the 'Golgi blockade' hypothesis) may represent the subcellular mechanism leading to MCTP-induced megalocytosis. In the present study, we investigated the applicability of the Golgi blockade hypothesis to epithelial cells. MCTP induced marked megalocytosis in cultures of lung A549 and breast MCF-7 cells. This was associated with a change in the distribution of the cis-Golgi scaffolding protein GM130 from a discrete juxtanuclear localization to a circumnuclear distribution consistent with an anterograde block of GM130 trafficking to/through the Golgi. There was also a loss of plasma membrane caveolin-1 and E-cadherin, cortical actin together with a circumnuclear accumulation of clathrin heavy chain (CHC) and α-tubulin. Flotation analyses revealed losses/alterations in the association of caveolin-1, E-cadherin and CHC with raft microdomains. Moreover, megalocytosis was accompanied by an enhanced unfolded protein response (UPR) as evidenced by nuclear translocation of Ire1α and glucose regulated protein 58 (GRP58/ER-60/ERp57) and a circumnuclear accumulation of PERK kinase and protein disulfide isomerase (PDI). These data further support the hypothesis that an MCTP-induced Golgi blockade and enhanced UPR may represent the subcellular mechanism leading to enlargement of ER and Golgi and subsequent megalocytosis

A membrane-anchored E-type endo-1,4-beta-glucanase is localized on Golgi and plasma membranes of higher plants.

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Brummell, D A; Catala, C; Lashbrook, C C; Bennett, A B

1997-04-29

Endo-1,4-beta-D-glucanases (EGases, EC 3.2.1.4) are enzymes produced in bacteria, fungi, and plants that hydrolyze polysaccharides possessing a 1,4-beta-D-glucan backbone. All previously identified plant EGases are E-type endoglucanases that possess signal sequences for endoplasmic reticulum entry and are secreted to the cell wall. Here we report the characterization of a novel E-type plant EGase (tomato Cel3) with a hydrophobic transmembrane domain and structure typical of type II integral membrane proteins. The predicted protein is composed of 617 amino acids and possesses seven potential sites for N-glycosylation. Cel3 mRNA accumulates in young vegetative tissues with highest abundance during periods of rapid cell expansion, but is not hormonally regulated. Antibodies raised to a recombinant Cel3 protein specifically recognized three proteins, with apparent molecular masses of 93, 88, and 53 kDa, in tomato root microsomal membranes separated by sucrose density centrifugation. The 53-kDa protein comigrated in the gradient with plasma membrane markers, the 88-kDa protein with Golgi membrane markers, and the 93-kDa protein with markers for both Golgi and plasma membranes. EGase enzyme activity was also found in regions of the density gradient corresponding to both Golgi and plasma membranes, suggesting that Cel3 EGase resides in both membrane systems, the sites of cell wall polymer biosynthesis. The in vivo function of Cel3 is not known, but the only other known membrane-anchored EGase is present in Agrobacterium tumefaciens where it is required for cellulose biosynthesis.

Evidence that proliferation of golgi apparatus depends on both de novo generation from the endoplasmic reticulum and formation from pre-existing stacks during the growth of tobacco BY-2 cells.

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Abiodun, Moses Olabiyi; Matsuoka, Ken

2013-04-01

In higher plants, the numbers of cytoplasmic-distributed Golgi stacks differ based on function, age and cell type. It has not been clarified how the numbers are controlled, whether all the Golgi apparatus in a cell function equally and whether the increase in Golgi number is a result of the de novo formation from the endoplasmic reticulum (ER) or fission of pre-existing stacks. A tobacco prolyl 4-hydroxylase (NtP4H1.1), which is a cis-Golgi-localizing type II membrane protein, was tagged with a photoconvertible fluorescent protein, mKikGR (monomeric Kikume green red), and expressed in tobacco bright yellow 2 (BY-2) cells. Transformed cells were exposed to purple light to convert the fluorescence from green to red. A time-course analysis after the conversion revealed a progressive increase in green puncta and a decrease in the red puncta. From 3 to 6 h, we observed red, yellow and green fluorescent puncta corresponding to pre-existing Golgi; Golgi containing both pre-existing and newly synthesized protein; and newly synthesized Golgi. Analysis of the number and fluorescence of Golgi at different phases of the cell cycle suggested that an increase in Golgi number with both division and de novo synthesis occurred concomitantly with DNA replication. Investigation with different inhibitors suggested that the formation of new Golgi and the generation of Golgi containing both pre-existing and newly synthesized protein are mediated by different machineries. These results and modeling based on quantified results indicate that the Golgi apparatuses in tobacco BY-2 cells are not uniform and suggest that both de novo synthesis from the ER and Golgi division contribute almost equally to the increase in proliferating cells.

Live-cell imaging of dual-labeled Golgi stacks in tobacco BY-2 cells reveals similar behaviors for different cisternae during movement and brefeldin A treatment.

Science.gov (United States)

Madison, Stephanie L; Nebenführ, Andreas

2011-09-01

In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A (BFA)-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a remarkable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addition, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.

Disease-specific structural changes in thalamus and dentatorubrothalamic tract in progressive supranuclear palsy

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Surova, Yulia; Hall, Sara; Widner, Haakan [Lund University, Department of Clinical Sciences, Lund (Sweden); Skaane University Hospital, Department of Neurology, Lund (Sweden); Nilsson, Markus [Lund University, Lund University Bioimaging Center, Lund (Sweden); Laett, Jimmy [Skaane University Hospital, Center for Medical Imaging and Physiology, Lund (Sweden); Lampinen, Bjoern [Lund University, Department of Medical Radiation Physics, Lund (Sweden); Lindberg, Olof [Malmoe, Lund University, Department of Clinical Sciences, Malmoe (Sweden); Nilsson, Christer [Skaane University Hospital, Department of Neurology, Lund (Sweden); Malmoe, Lund University, Department of Clinical Sciences, Malmoe (Sweden); Westen, Danielle van [Lund University, Department of Clinical Sciences, Lund (Sweden); Skaane University Hospital, Center for Medical Imaging and Physiology, Lund (Sweden); Hansson, Oskar [Malmoe, Lund University, Department of Clinical Sciences, Malmoe (Sweden); Skaane University Hospital, Memory Clinic, Lund (Sweden)

2015-11-15

The aim of this study is to identify disease-specific changes of the thalamus, basal ganglia, pons, and midbrain in patients with progressive supranuclear palsy (PSP), Parkinson's disease (PD), and multiple system atrophy with predominant parkinsonism (MSA-P) using diffusion tensor imaging and volumetric analysis. MRI diffusion and volumetric data were acquired in a derivation of 30 controls and 8 patients with PSP and a validation cohort comprised of controls (n = 21) and patients with PSP (n = 27), PD (n = 10), and MSA-P (n = 11). Analysis was performed using regions of interest (ROI), tract-based spatial statistic (TBSS), and tractography and results compared between diagnostic groups. In the derivation cohort, we observed increased mean diffusivity (MD) in the thalamus, superior cerebellar peduncle, and the midbrain in PSP compared to controls. Furthermore, volumetric analysis showed reduced thalamic volumes in PSP. In the validation cohort, the observations of increased MD were replicated by ROI-based analysis and in the thalamus by TBSS-based analysis. Such differences were not found for patients with PD in any of the cohorts. Tractography of the dentatorubrothalamic tract (DRTT) showed increased MD in PSP patients from both cohorts compared to controls and in the validation cohort in PSP compared to PD and MSA patients. Increased MD in the thalamus and along the DRTT correlated with disease stage and motor function in PSP. Patients with PSP, but not PD or MSA-P, exhibit signs of structural abnormalities in the thalamus and in the DRTT. These changes are associated with disease stage and impaired motor function. (orig.)

Disease-specific structural changes in thalamus and dentatorubrothalamic tract in progressive supranuclear palsy

International Nuclear Information System (INIS)

Surova, Yulia; Hall, Sara; Widner, Haakan; Nilsson, Markus; Laett, Jimmy; Lampinen, Bjoern; Lindberg, Olof; Nilsson, Christer; Westen, Danielle van; Hansson, Oskar

2015-01-01

The aim of this study is to identify disease-specific changes of the thalamus, basal ganglia, pons, and midbrain in patients with progressive supranuclear palsy (PSP), Parkinson's disease (PD), and multiple system atrophy with predominant parkinsonism (MSA-P) using diffusion tensor imaging and volumetric analysis. MRI diffusion and volumetric data were acquired in a derivation of 30 controls and 8 patients with PSP and a validation cohort comprised of controls (n = 21) and patients with PSP (n = 27), PD (n = 10), and MSA-P (n = 11). Analysis was performed using regions of interest (ROI), tract-based spatial statistic (TBSS), and tractography and results compared between diagnostic groups. In the derivation cohort, we observed increased mean diffusivity (MD) in the thalamus, superior cerebellar peduncle, and the midbrain in PSP compared to controls. Furthermore, volumetric analysis showed reduced thalamic volumes in PSP. In the validation cohort, the observations of increased MD were replicated by ROI-based analysis and in the thalamus by TBSS-based analysis. Such differences were not found for patients with PD in any of the cohorts. Tractography of the dentatorubrothalamic tract (DRTT) showed increased MD in PSP patients from both cohorts compared to controls and in the validation cohort in PSP compared to PD and MSA patients. Increased MD in the thalamus and along the DRTT correlated with disease stage and motor function in PSP. Patients with PSP, but not PD or MSA-P, exhibit signs of structural abnormalities in the thalamus and in the DRTT. These changes are associated with disease stage and impaired motor function. (orig.)

Characteristics of Nonmotor Symptoms in Progressive Supranuclear Palsy

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Ruwei Ou

2016-01-01

Full Text Available Objectives. To explore the clinical correlates of nonmotor symptoms (NMS in progressive supranuclear palsy (PSP and their differences from healthy controls and patients with Parkinson’s disease (PD. Methods. Twenty-seven PSP patients, 27 age- and gender-matched healthy controls (HC, and 27 age- and gender-matched PD patients were included for this case-control study. NMS were assessed using the Nonmotor Symptoms Scale (NMSS, including 9 domains. Results. All PSP patients reported NMS. The frequency and severity of “sleep/fatigue,” “mood/apathy,” “attention/memory,” “gastrointestinal,” “sexual dysfunction,” and “miscellaneous” domains in PSP group were significantly higher than those in HC group (P<0.05. The frequency of “mood/apathy,” “attention/memory,” and “sexual dysfunction” domains and the severity of “attention/memory” and “gastrointestinal” domains in PSP group were significantly higher than those in PD group (P<0.05. The “attention/memory” domain in PSP had a significant but weak-to-moderate correlation with age (R=0.387, P=0.046 and onset age (R=0.406, P=0.036. Conclusions. NMS are common in PSP patients. Patients with PSP seem to be subjected to more frequent and severe specific NMS compared to healthy aging subjects and PD patients. Older PSP patients and late-onset patients are likely to be subjected to cognitive decline.

A Quantitative Golgi Study of Dendritic Morphology in the Mice Striatal Medium Spiny Neurons

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Ana Hladnik

2017-04-01

Full Text Available In this study we have provided a detailed quantitative morphological analysis of medium spiny neurons (MSNs in the mice dorsal striatum and determined the consistency of values among three groups of animals obtained in different set of experiments. Dendritic trees of 162 Golgi Cox (FD Rapid GolgiStain Kit impregnated MSNs from 15 adult C57BL/6 mice were 3-dimensionally reconstructed using Neurolucida software, and parameters of dendritic morphology have been compared among experimental groups. The parameters of length and branching pattern did not show statistically significant difference and were highly consistent among groups. The average neuronal soma surface was between 160 μm2 and 180 μm2, and the cells had 5–6 primary dendrites with close to 40 segments per neuron. Sholl analysis confirmed regular pattern of dendritic branching. The total length of dendrites was around 2100 μm with the average length of individual branching (intermediate segment around 22 μm and for the terminal segment around 100 μm. Even though each experimental group underwent the same strictly defined protocol in tissue preparation and Golgi staining, we found inconsistency in dendritic volume and soma surface. These changes could be methodologically influenced during the Golgi procedure, although without affecting the dendritic length and tree complexity. Since the neuronal activity affects the dendritic thickness, it could not be excluded that observed volume inconsistency was related with functional states of neurons prior to animal sacrifice. Comprehensive analyses of tree complexity and dendritic length provided here could serve as an additional tool for understanding morphological variability in the most numerous neuronal population of the striatum. As reference values they could provide basic ground for comparisons with the results obtained in studies that use various models of genetically modified mice in explaining different pathological conditions that

Pittsburgh Compound B and AV-1451 positron emission tomography assessment of molecular pathologies of Alzheimer's disease in progressive supranuclear palsy.

Science.gov (United States)

Whitwell, Jennifer L; Ahlskog, J Eric; Tosakulwong, Nirubol; Senjem, Matthew L; Spychalla, Anthony J; Petersen, Ronald C; Jack, Clifford R; Lowe, Val J; Josephs, Keith A

2018-03-01

Little is known about Alzheimer's disease molecular proteins, beta-amyloid and paired helical filament (PHF) tau, in progressive supranuclear palsy (PSP). Recent techniques have been developed to allow for investigations of these proteins in PSP. We determined the frequency of beta-amyloid deposition in PSP, and whether beta-amyloid deposition in PSP is associated with PHF-tau deposition pattern, or clinical features. Thirty probable PSP participants underwent MRI, [ 18 F]AV-1451 PET and Pittsburgh compound B (PiB) PET. Apolipoprotein (APOE) genotyping was also performed. A global PiB standard-uptake value ratio (SUVR) was calculated. AV-1451 SUVRs were calculated for a set of Alzheimer's disease (AD)-related regions and a set of PSP-related regions. Voxel-level analyses were conducted to assess for differences in AV-1451 uptake patterns and MRI atrophy between PiB(+) and PiB(-) cases compared to 60 normal PiB(-) controls. Statistical testing for correlations and associations between variables of interest were also performed. Twelve subjects (40%) showed beta-amyloid deposition. Higher PiB SUVR correlated with older age but not with AV-1451 SUVR in the AD- or PSP-related regions. Higher AV-1451 SUVR in AD-related regions was associated with higher AV-1451 SUVR in PSP-related regions. We found little evidence for beta-amyloid related differences in clinical metrics, proportion of APOE e4 carriers, pattern of AV-1451 uptake, or pattern of atrophy. Beta-amyloid deposition occurs in a relatively high proportion of PSP subjects. Unlike in Alzheimer's disease, however, there is little evidence that beta-amyloid, and PHF-tau, play a significant role in neurodegeneration in PSP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ceramide transport from endoplasmic reticulum to Golgi apparatus is not vesicle-mediated

NARCIS (Netherlands)

Kok, JW; Babia, T; Klappe, K; Egea, G; Hoekstra, D

1998-01-01

Ceramide (Cer) transfer from the endoplasmic reticulum (ER) to the Golgi apparatus was measured under conditions that block vesicle-mediated protein transfer. This was done either in intact cells by reducing the incubation temperature to 15 degrees C, or in streptolysin O-permeabilized cells by

Proliferation of the Golgi apparatus in tobacco BY-2 cells during cell proliferation after release from the stationary phase of growth.

Science.gov (United States)

Abiodun, Moses; Matsuoka, Ken

2013-08-01

We have recently developed a new method aimed at mass photo-conversion of photo-convertible fluorescence protein (PFP) fluorescence in transformed tobacco BY-2 cells. Using this method we reported recently that the Golgi apparatus is generated by the de novo formation from ER and the division of pre-existing Golgi stacks with similar extents In this work we report that the proliferation of the Golgi apparatus in tobacco cells that enter the growing cycle from the non-dividing cycle is quite similar to that in rapidly growing cells and that de novo formation from the ER and division of pre-existing stacks seems to contribute almost equally to the proliferation.

Golgi-associated Rab14, a new regulator for Chlamydia trachomatis infection outcome.

Science.gov (United States)

Capmany, Anahí; Leiva, Natalia; Damiani, María Teresa

2011-09-01

Chlamydia trachomatis is the causing agent of the most frequent bacterial sexually-transmitted diseases worldwide and is an underlying cause of chronic pelvic inflammatory diseases and cervical cancer. It is an obligate intracellular bacterium that establishes a close relationship with the Golgi complex and parasites the biosynthetic machinery of host cells. In a recent study, we have demonstrated that Rab14, a newly-described Golgi-associated Rab, is involved in the delivery of sphingolipids to the growing bacteria-containing vacuole. The interference with Rab14-controlled trafficking pathways delays chlamydial inclusion enlargement, decreases bacterial lipid uptake, negatively impact on bacterial differentiation, and reduces bacterial progeny and infectivity. C. trachomatis manipulation of host trafficking pathways for the acquisition of endogenously-biosynthesized nutrients arises as one of the characteristics of this highly evolved pathogen. The development of therapeutic strategies targeted to interfere with bacterium-host cell interaction is a new challenge for pharmacological approaches to control chlamydial infections.

Hsp20 Protects against Oxygen-Glucose Deprivation/Reperfusion-Induced Golgi Fragmentation and Apoptosis through Fas/FasL Pathway

Directory of Open Access Journals (Sweden)

Bingwu Zhong

2015-01-01

Full Text Available Cerebral ischemia-reperfusion injury plays an important role in the development of tissue injury after acute ischemic stroke. Finding effective neuroprotective agents has become a priority in the treatment of ischemic stroke. The Golgi apparatus (GA is a pivotal organelle and its protection is an attractive target in the treatment of cerebral ischemia-reperfusion injury. Protective effects of Hsp20, a potential cytoprotective agent due to its chaperone-like activity and involvement in regulation of many vital processes, on GA were assessed in an ischemia-reperfusion injury model. Mouse neuroblastoma Neuro2a (N2a cells were subjected to oxygen-glucose deprivation/reperfusion (OGDR insult. OGDR induces Golgi fragmentation, apoptosis, and p115 cleavage in N2a cells. However, transfection with Hsp20 significantly attenuates OGDR-induced Golgi fragmentation and apoptosis. Hsp20 interacts with Bax, decreases FasL and Bax expression, and inhibits caspases 3 and p115 cleavage in N2a cells exposed to OGDR. Our data demonstrate that increased Hsp20 expression protects against OGDR-induced Golgi fragmentation and apoptosis, likely through interaction with Bax and subsequent amelioration of the OGDR-induced elevation in p115 cleavage via the Fas/FasL signaling pathway. This neuroprotective potential of Hsp20 against OGDR insult and the underlying mechanism will pave the way for its potential clinical application for cerebral ischemia-reperfusion related disorders.

Neutral sphingomyelinase (SMPD3) deficiency disrupts the Golgi secretory pathway and causes growth inhibition

Science.gov (United States)

Stoffel, Wilhelm; Hammels, Ina; Jenke, Bitta; Binczek, Erika; Schmidt-Soltau, Inga; Brodesser, Susanne; Schauss, Astrid; Etich, Julia; Heilig, Juliane; Zaucke, Frank

2016-01-01

Systemic loss of neutral sphingomyelinase (SMPD3) in mice leads to a novel form of systemic, juvenile hypoplasia (dwarfism). SMPD3 deficiency in mainly two growth regulating cell types contributes to the phenotype, in chondrocytes of skeletal growth zones to skeletal malformation and chondrodysplasia, and in hypothalamic neurosecretory neurons to systemic hypothalamus–pituitary–somatotropic hypoplasia. The unbiased smpd3−/− mouse mutant and derived smpd3−/− primary chondrocytes were instrumental in defining the enigmatic role underlying the systemic and cell autonomous role of SMPD3 in the Golgi compartment. Here we describe the unprecedented role of SMPD3. SMPD3 deficiency disrupts homeostasis of sphingomyelin (SM), ceramide (Cer) and diacylglycerol (DAG) in the Golgi SMPD3-SMS1 (SM-synthase1) cycle. Cer and DAG, two fusogenic intermediates, modify the membrane lipid bilayer for the initiation of vesicle formation and transport. Dysproteostasis, unfolded protein response, endoplasmic reticulum stress and apoptosis perturb the Golgi secretory pathway in the smpd3−/− mouse. Secretion of extracellular matrix proteins is arrested in chondrocytes and causes skeletal malformation and chondrodysplasia. Similarly, retarded secretion of proteo-hormones in hypothalamic neurosecretory neurons leads to hypothalamus induced combined pituitary hormone deficiency. SMPD3 in the regulation of the protein vesicular secretory pathway may become a diagnostic target in the etiology of unknown forms of juvenile growth and developmental inhibition. PMID:27882938

Overexpression of Rab22a hampers the transport between endosomes and the Golgi apparatus

International Nuclear Information System (INIS)

Mesa, Rosana; Magadan, Javier; Barbieri, Alejandro; Lopez, Cecilia; Stahl, Philip D.; Mayorga, Luis S.

2005-01-01

The transport and sorting of soluble and membrane-associated macromolecules arriving at endosomal compartments require a complex set of Rab proteins. Rab22a has been localized to the endocytic compartment; however, very little is known about the function of Rab22a and inconsistent results have been reported in studies performed in different cell lines. To characterize the function of Rab22a in endocytic transport, the wild-type protein (Rab22a WT), a hydrolysis-deficient mutant (Rab22a Q64L), and a mutant with reduced affinity for GTP (Rab22a S19N) were expressed in CHO cells. None of the three Rab22a constructs affected the transport of rhodamine-dextran to lysosomes, the digestion of internalized proteins, or the lysosomal localization of cathepsin D. In contrast with the mild effect of Rab22a on the endosome-lysosome route, cells expressing Rab22a WT and Rab22a Q64L presented a strong delay in the retrograde transport of cholera toxin from endosomes to the Golgi apparatus. Moreover, these cells accumulated the cation independent mannose 6-phosphate receptor in endosomes. These observations indicate that Rab22a can affect the trafficking from endosomes to the Golgi apparatus probably by promoting fusion among endosomes and impairing the proper segregation of membrane domains required for targeting to the trans-Golgi network (TGN)

Beyond the midbrain atrophy: wide spectrum of structural MRI finding in cases of pathologically proven progressive supranuclear palsy

International Nuclear Information System (INIS)

Sakurai, Keita; Tokumaru, Aya M.; Shimoji, Keigo; Murayama, Shigeo; Kanemaru, Kazutomi; Morimoto, Satoru; Aiba, Ikuko; Nakagawa, Motoo; Ozawa, Yoshiyuki; Shimohira, Masashi; Shibamoto, Yuta; Matsukawa, Noriyuki; Hashizume, Yoshio

2017-01-01

Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes. With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated. In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases. It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases. (orig.)

Beyond the midbrain atrophy: wide spectrum of structural MRI finding in cases of pathologically proven progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Sakurai, Keita; Tokumaru, Aya M.; Shimoji, Keigo [Tokyo Metropolitan Medical Center of Gerontology, Department of Diagnostic Radiology, Tokyo (Japan); Murayama, Shigeo; Kanemaru, Kazutomi; Morimoto, Satoru [Tokyo Metropolitan Geriatric Hospital, Department of Neurology, Tokyo (Japan); Aiba, Ikuko [National Hospital Organization Higashi Nagoya National Hospital, Department of Neurology, Nagoya (Japan); Nakagawa, Motoo; Ozawa, Yoshiyuki; Shimohira, Masashi; Shibamoto, Yuta [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, Nagoya (Japan); Matsukawa, Noriyuki [Nagoya City University Graduate School of Medical Sciences, Department of Neurology and Neuroscience, Nagoya (Japan); Hashizume, Yoshio [Fukushimura Hospital, Choju Medical Institute, Toyohashi (Japan)

2017-05-15

Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes. With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated. In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases. It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases. (orig.)

TCR¿ is transported to and retained in the Golgi apparatus independently of other TCR chains: implications for TCR assembly

DEFF Research Database (Denmark)

Dietrich, J; Kastrup, J; Lauritsen, Jens Peter Holst

1999-01-01

. This study focused on the intracellular localization and transport of partially assembled TCR complexes as determined by confocal microscopy analyses. We found that none of the TCR chains except for TCRzeta were allowed to exit the ER in T cell variants in which the hexameric CD3gammaepsilonTi alphabetaCD3...... deltaepsilon complex was not formed. Interestingly, TCRzeta was exported from the ER independently of other TCR chains and was predominantly located in a compartment identified as the Golgi apparatus. Furthermore, in the TCRzeta-negative cell line MA5.8, the hexameric CD3gammaepsilonTi alphabetaCD3...... the ER to the Golgi apparatus independently of each other and that these partial TCR complexes are unable to be efficiently expressed at the cell surface suggest that final TCR assembly occurs in the Golgi apparatus....

Dynamin-like protein 1 at the Golgi complex: A novel component of the sorting/targeting machinery en route to the plasma membrane

International Nuclear Information System (INIS)

Bonekamp, Nina A.; Vormund, Kerstin; Jacob, Ralf; Schrader, Michael

2010-01-01

The final step in the liberation of secretory vesicles from the trans-Golgi network (TGN) involves the mechanical action of the large GTPase dynamin as well as conserved dynamin-independent fission mechanisms, e.g. mediated by Brefeldin A-dependent ADP-ribosylated substrate (BARS). Another member of the dynamin family is the mammalian dynamin-like protein 1 (DLP1/Drp1) that is known to constrict and tubulate membranes, and to divide mitochondria and peroxisomes. Here, we examined a potential role for DLP1 at the Golgi complex. DLP1 localized to the Golgi complex in some but not all cell lines tested, thus explaining controversial reports on its cellular distribution. After silencing of DLP1, an accumulation of the apical reporter protein YFP-GL-GPI, but not the basolateral reporter VSVG-SP-GFP at the Golgi complex was observed. A reduction in the transport of YFP-GL-GPI to the plasma membrane was confirmed by surface immunoprecipitation and TGN-exit assays. In contrast, YFP-GL-GPI trafficking was not disturbed in cells silenced for BARS, which is involved in basolateral sorting and trafficking of VSVG-SP-GFP in COS-7 cells. Our data indicate a new role for DLP1 at the Golgi complex and thus a role for DLP1 as a novel component of the apical sorting machinery at the TGN is discussed.

Impaired perception of surface tilt in progressive supranuclear palsy.

Directory of Open Access Journals (Sweden)

Marian L Dale

Full Text Available Progressive supranuclear palsy (PSP is characterized by early postural instability and backward falls. The mechanisms underlying backward postural instability in PSP are not understood. The aim of this study was to test the hypothesis that postural instability in PSP is a result of dysfunction in the perception of postural verticality.We gathered posturography data on 12 subjects with PSP to compare with 12 subjects with idiopathic Parkinson's Disease (PD and 12 healthy subjects. Objective tests of postural impairment included: dynamic sensory perception tests of gravity and of surface oscillations, postural responses to surface perturbations, the sensory organization test of postural sway under altered sensory conditions and limits of stability in stance.Perception of toes up (but not toes down surface tilt was reduced in subjects with PSP compared to both control subjects (p≤0.001 standing, p≤0.007 seated and subjects with PD (p≤0.03 standing, p≤0.04 seated. Subjects with PSP, PD and normal controls accurately perceived the direction of gravity when standing on a tilting surface. Unlike PD and control subjects, subjects with PSP exerted less postural corrective torque in response to toes up surface tilts.Difficulty perceiving backward tilt of the surface or body may account for backward falls and postural impairments in patients with PSP. These observations suggest that abnormal central integration of sensory inputs for perception of body and surface orientation contributes to the pathophysiology of postural instability in PSP.

Short length transmembrane domains having voluminous exoplasmic halves determine retention of Type II membrane proteins in the Golgi complex

OpenAIRE

Quiroga, Rodrigo; Trenchi, Alejandra; Gonzalez Montoro, Ayelén; Valdez, Javier Esteban; Maccioni, Hugo Jose Fernando

2017-01-01

It is still unclear why some proteins that travel along the secretory pathway are retained in the Golgi complex whereas others make their way to the plasma membrane. Recent bioinformatic analyses on a large number of single-spanning membrane proteins support the hypothesis that specific features of the transmembrane domain (TMD) are relevant to the sorting of these proteins to particular organelles. Here we experimentally test this hypothesis for Golgi and plasma membrane proteins. Using the ...

GABARAP activates ULK1 and traffics from the centrosome dependent on Golgi partners WAC and GOLGA2/GM130

OpenAIRE

Joachim, Justin; Tooze, Sharon A.

2016-01-01

ABSTRACT WAC and GOLGA2/GM130 are 2 Golgi proteins that affect autophagy; however, their mechanism of action was unknown. We have shown that WAC binding to GOLGA2 at the Golgi displaces GABARAP from GOLGA2 to allow the maintenance of a nonlipidated centrosomal GABARAP pool. Centrosomal GABARAP can traffic to autophagic structures during starvation. In addition GABARAP specifically promotes ULK1 activation and this is independent of GABARAP lipidation but likely requires a LIR-mediated GABARAP...

Hepatic trans-Golgi action coordinated by the GTPase ARFRP1 is crucial for lipoprotein lipidation and assembly[S

Science.gov (United States)

Hesse, Deike; Radloff, Katrin; Jaschke, Alexander; Lagerpusch, Merit; Chung, Bomee; Tailleux, Anne; Staels, Bart; Schürmann, Annette

2014-01-01

The liver is a major organ in whole body lipid metabolism and malfunctioning can lead to various diseases including dyslipidemia, fatty liver disease, and type 2 diabetes. Triglycerides and cholesteryl esters are packed in the liver as very low density lipoproteins (VLDLs). Generation of these lipoproteins is initiated in the endoplasmic reticulum and further maturation likely occurs in the Golgi. ADP-ribosylation factor-related protein 1 (ARFRP1) is a small trans-Golgi-associated guanosine triphosphatase (GTPase) that regulates protein sorting and is required for chylomicron lipidation and assembly in the intestine. Here we show that the hepatocyte-specific deletion of Arfrp1 (Arfrp1liv−/−) results in impaired VLDL lipidation leading to reduced plasma triglyceride levels in the fasted state as well as after inhibition of lipoprotein lipase activity by Triton WR-1339. In addition, the concentration of ApoC3 that comprises 40% of protein mass of secreted VLDLs is markedly reduced in the plasma of Arfrp1liv−/− mice but accumulates in the liver accompanied by elevated triglycerides. Fractionation of Arfrp1liv−/− liver homogenates reveals more ApoB48 and a lower concentration of triglycerides in the Golgi compartments than in the corresponding fractions from control livers. In conclusion, ARFRP1 and the Golgi apparatus play an important role in lipoprotein maturation in the liver by influencing lipidation and assembly of proteins to the lipid particles. PMID:24186947

Automatic classification of patients with idiopathic Parkinson's disease and progressive supranuclear palsy using diffusion MRI datasets

Science.gov (United States)

Talai, Sahand; Boelmans, Kai; Sedlacik, Jan; Forkert, Nils D.

2017-03-01

Parkinsonian syndromes encompass a spectrum of neurodegenerative diseases, which can be classified into various subtypes. The differentiation of these subtypes is typically conducted based on clinical criteria. Due to the overlap of intra-syndrome symptoms, the accurate differential diagnosis based on clinical guidelines remains a challenge with failure rates up to 25%. The aim of this study is to present an image-based classification method of patients with Parkinson's disease (PD) and patients with progressive supranuclear palsy (PSP), an atypical variant of PD. Therefore, apparent diffusion coefficient (ADC) parameter maps were calculated based on diffusion-tensor magnetic resonance imaging (MRI) datasets. Mean ADC values were determined in 82 brain regions using an atlas-based approach. The extracted mean ADC values for each patient were then used as features for classification using a linear kernel support vector machine classifier. To increase the classification accuracy, a feature selection was performed, which resulted in the top 17 attributes to be used as the final input features. A leave-one-out cross validation based on 56 PD and 21 PSP subjects revealed that the proposed method is capable of differentiating PD and PSP patients with an accuracy of 94.8%. In conclusion, the classification of PD and PSP patients based on ADC features obtained from diffusion MRI datasets is a promising new approach for the differentiation of Parkinsonian syndromes in the broader context of decision support systems.

GABARAP activates ULK1 and traffics from the centrosome dependent on Golgi partners WAC and GOLGA2/GM130.

Science.gov (United States)

Joachim, Justin; Tooze, Sharon A

2016-05-03

WAC and GOLGA2/GM130 are 2 Golgi proteins that affect autophagy; however, their mechanism of action was unknown. We have shown that WAC binding to GOLGA2 at the Golgi displaces GABARAP from GOLGA2 to allow the maintenance of a nonlipidated centrosomal GABARAP pool. Centrosomal GABARAP can traffic to autophagic structures during starvation. In addition GABARAP specifically promotes ULK1 activation and this is independent of GABARAP lipidation but likely requires a LIR-mediated GABARAP-ULK1 interaction.

PI3K class II α regulates δ-opioid receptor export from the trans-Golgi network.

Science.gov (United States)

Shiwarski, Daniel J; Darr, Marlena; Telmer, Cheryl A; Bruchez, Marcel P; Puthenveedu, Manojkumar A

2017-08-01

The interplay between signaling and trafficking by G protein-coupled receptors (GPCRs) has focused mainly on endocytic trafficking. Whether and how surface delivery of newly synthesized GPCRs is regulated by extracellular signals is less understood. Here we define a signaling-regulated checkpoint at the trans -Golgi network (TGN) that controls the surface delivery of the delta opioid receptor (δR). In PC12 cells, inhibition of phosphoinositide-3 kinase (PI3K) activity blocked export of newly synthesized δR from the Golgi and delivery to the cell surface, similar to treatment with nerve growth factor (NGF). Depletion of class II phosphoinositide-3 kinase α (PI3K C2A), but not inhibition of class I PI3K, blocked δR export to comparable levels and attenuated δR-mediated cAMP inhibition. NGF treatment displaced PI3K C2A from the Golgi and optogenetic recruitment of the PI3K C2A kinase domain to the TGN-induced δR export downstream of NGF. Of importance, PI3K C2A expression promotes export of endogenous δR in primary trigeminal ganglion neurons. Taken together, our results identify PI3K C2A as being required and sufficient for δR export and surface delivery in neuronal cells and suggest that it could be a key modulator of a novel Golgi export checkpoint that coordinates GPCR delivery to the surface. © 2017 Shiwarski et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Endoplasmic reticulum-to-Golgi transitions upon herpes virus infection [version 2; referees: 1 approved, 3 approved with reservations

Directory of Open Access Journals (Sweden)

Peter Wild

2018-02-01

Full Text Available Background: Herpesvirus capsids are assembled in the nucleus, translocated to the perinuclear space by budding, acquiring tegument and envelope, or released to the cytoplasm via impaired nuclear envelope. One model proposes that envelopment, “de-envelopment” and “re-envelopment” is essential for production of infectious virus. Glycoproteins gB/gH were reported to be essential for de-envelopment, by fusion of the “primary” envelope with the outer nuclear membrane. Yet, a high proportion of enveloped virions generated from genomes with deleted gB/gH were found in the cytoplasm and extracellular space, suggesting the existence of alternative exit routes. Methods: We investigated the relatedness between the nuclear envelope and membranes of the endoplasmic reticulum and Golgi complex, in cells infected with either herpes simplex virus 1 (HSV-1 or a Us3 deletion mutant thereof, or with bovine herpesvirus 1 (BoHV-1 by transmission and scanning electron microscopy, employing freezing technique protocols. Results:  The Golgi complex is a compact entity in a juxtanuclear position covered by a membrane on the cis face. Golgi membranes merge with membranes of the endoplasmic reticulum forming an entity with the perinuclear space. All compartments contained enveloped virions. After treatment with brefeldin A, HSV-1 virions aggregated in the perinuclear space and endoplasmic reticulum, while infectious progeny virus was still produced. Conclusions: The data suggest that virions derived by budding at nuclear membranes are intraluminally transported from the perinuclear space via Golgi -endoplasmic reticulum transitions into Golgi cisternae for packaging. Virions derived by budding at nuclear membranes are infective like Us3 deletion mutants, which  accumulate in the perinuclear space. Therefore, i de-envelopment followed by re-envelopment is not essential for production of infective progeny virus, ii the process taking place at the outer nuclear

3D Printing of Plant Golgi Stacks from Their Electron Tomographic Models.

Science.gov (United States)

Mai, Keith Ka Ki; Kang, Madison J; Kang, Byung-Ho

2017-01-01

Three-dimensional (3D) printing is an effective tool for preparing tangible 3D models from computer visualizations to assist in scientific research and education. With the recent popularization of 3D printing processes, it is now possible for individual laboratories to convert their scientific data into a physical form suitable for presentation or teaching purposes. Electron tomography is an electron microscopy method by which 3D structures of subcellular organelles or macromolecular complexes are determined at nanometer-level resolutions. Electron tomography analyses have revealed the convoluted membrane architectures of Golgi stacks, chloroplasts, and mitochondria. But the intricacy of their 3D organizations is difficult to grasp from tomographic models illustrated on computer screens. Despite the rapid development of 3D printing technologies, production of organelle models based on experimental data with 3D printing has rarely been documented. In this chapter, we present a simple guide to creating 3D prints of electron tomographic models of plant Golgi stacks using the two most accessible 3D printing technologies.

Parkinson disease and progressive supranuclear palsy: protein expression in skin.

Science.gov (United States)

Rodríguez-Leyva, Ildefonso; Chi-Ahumada, Erika G; Carrizales, Juan; Rodríguez-Violante, Mayela; Velázquez-Osuna, Salvador; Medina-Mier, Verónica; Martel-Gallegos, María G; Zarazúa, Sergio; Enríquez-Macías, Lourdes; Castro, Adriana; Calderón-Garcidueñas, Ana Laura; Jiménez-Capdeville, María E

2016-03-01

This study characterizes the expression of tau (p-tau) and α-synuclein (α-syn) by immunohistochemistry in the skin of three different populations: healthy control (HC), Parkinson disease (PD), and progressive supranuclear paralysis (PSP) subjects, with the purpose of finding a biomarker that could differentiate between subjects with PD and PSP. We evaluated the presence of p-tau and α-syn in a pilot study in the skin of three distinct groups of patients: 17 healthy subjects, 17 patients with PD, and 10 patients with PSP. Four millimeters punch biopsies were obtained from the occipital area and analyzed by immunohistochemistry using antibodies against α-syn and phosphorylated species of tau. PHF (paired helical filaments) antibody identifies p-tau in both normal and pathological conditions and AT8 recognizes p-tau characteristic of pathological conditions. Differences between the three groups were assessed by quantification of immunopositive areas in the epidermis. The immunopositivity pattern of p-tau and α-syn was significantly different among the three groups. Healthy subjects showed minimal staining using AT8 and α-syn. The PD group showed significantly higher α-syn and AT8 immunopositivity, while the PSP group only expressed higher AT8 immunopositivity than HCs. These data suggest that the skin reflects brain pathology. Therefore, immunohistochemical analysis of p-tau and α-syn in the skin can be useful for further characterization of PD and PSP.

FAM21 directs SNX27–retromer cargoes to the plasma membrane by preventing transport to the Golgi apparatus

Science.gov (United States)

Lee, Seongju; Chang, Jaerak; Blackstone, Craig

2016-01-01

The endosomal network maintains cellular homeostasis by sorting, recycling and degrading endocytosed cargoes. Retromer organizes the endosomal sorting pathway in conjunction with various sorting nexin (SNX) proteins. The SNX27–retromer complex has recently been identified as a major endosomal hub that regulates endosome-to-plasma membrane recycling by preventing lysosomal entry of cargoes. Here, we show that SNX27 directly interacts with FAM21, which also binds retromer, within the Wiskott–Aldrich syndrome protein and SCAR homologue (WASH) complex. This interaction is required for the precise localization of SNX27 at an endosomal subdomain as well as for recycling of SNX27-retromer cargoes. Furthermore, FAM21 prevents cargo transport to the Golgi apparatus by controlling levels of phosphatidylinositol 4-phosphate, which facilitates cargo dissociation at the Golgi. Together, our results demonstrate that the SNX27–retromer–WASH complex directs cargoes to the plasma membrane by blocking their transport to lysosomes and the Golgi. PMID:26956659

The Golgi localized bifunctional UDP-rhamnose/UDP-galactose transporter family of Arabidopsis

DEFF Research Database (Denmark)

Rautengarten, Carsten; Ebert, Berit; Moreno, Ignacio

2014-01-01

Delivery of nucleotide sugar substrates into the Golgi apparatus and endoplasmic reticulum for processes such as cell wall biosynthesis and protein glycosylation is critical for plant growth and development. Plant genomes encode large families of uncharacterized nucleotide sugar transporters that...

Apoptosis-linked Gene-2 (ALG-2)/Sec31 Interactions Regulate Endoplasmic Reticulum (ER)-to-Golgi Transport

Science.gov (United States)

Helm, Jared R.; Bentley, Marvin; Thorsen, Kevin D.; Wang, Ting; Foltz, Lauren; Oorschot, Viola; Klumperman, Judith; Hay, Jesse C.

2014-01-01

Luminal calcium released from secretory organelles has been suggested to play a regulatory role in vesicle transport at several steps in the secretory pathway; however, its functional roles and effector pathways have not been elucidated. Here we demonstrate for the first time that specific luminal calcium depletion leads to a significant decrease in endoplasmic reticulum (ER)-to-Golgi transport rates in intact cells. Ultrastructural analysis revealed that luminal calcium depletion is accompanied by increased accumulation of intermediate compartment proteins in COPII buds and clusters of unfused COPII vesicles at ER exit sites. Furthermore, we present several lines of evidence suggesting that luminal calcium affected transport at least in part through calcium-dependent interactions between apoptosis-linked gene-2 (ALG-2) and the Sec31A proline-rich region: 1) targeted disruption of ALG-2/Sec31A interactions caused severe defects in ER-to-Golgi transport in intact cells; 2) effects of luminal calcium and ALG-2/Sec31A interactions on transport mutually required each other; and 3) Sec31A function in transport required luminal calcium. Morphological phenotypes of disrupted ALG-2/Sec31A interactions were characterized. We found that ALG-2/Sec31A interactions were not required for the localization of Sec31A to ER exit sites per se but appeared to acutely regulate the stability and trafficking of the cargo receptor p24 and the distribution of the vesicle tether protein p115. These results represent the first outline of a mechanism that connects luminal calcium to specific protein interactions regulating vesicle trafficking machinery. PMID:25006245

Characterization of p28, a novel ERGIC/"cis"-Golgi protein, required for Golgi ribbon formation. pH measurements in the early secretory pathway "in vivo"

OpenAIRE

Kögler, Eva Jutta

2008-01-01

The secretory pathway of mammalian cells consists of several compartments. Transport between these organelles is accomplished via vesicular carriers or maturation. For non abundant proteins it is thought that transport receptors help the proteins to exit the ER in an effective way. The best characterized mammalian cargo receptor is ERGIC-53, which transports blood coagulation factor V and VIII, cathespin C and Z as well as alpha1-antitrypsin. It localizes to the ER Golgi intermediate compartm...

Selectivity of neuronal [3H]GABA accumulation in the visual cortex as revealed by Golgi staining of the labeled neurons

International Nuclear Information System (INIS)

Somogyi, P.; Freund, T.F.; Kisvarday, Z.F.; Halasz, N.

1981-01-01

[ 3 H]GABA was injected into the visual cortex of rats in vivo. The labeled amino acid was demonstrated by autoradiography using semithin sections of Golgi material. Selective accumulation was seen in the perikarya of Golgi-stained, gold-toned, aspinous stellate neurons. Spine-laden pyramidal-like cells did not show labeling. This method gives direct information about the dendritic arborization of a neuron, and its putative transmitter, and allows the identification of its synaptic connections. (Auth.)

Role of the Small GTPase Rho3 in Golgi/Endosome trafficking through functional interaction with adaptin in Fission Yeast.

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Ayako Kita

Full Text Available BACKGROUND: We had previously identified the mutant allele of apm1(+ that encodes a homolog of the mammalian µ1A subunit of the clathrin-associated adaptor protein-1 (AP-1 complex, and we demonstrated the role of Apm1 in Golgi/endosome trafficking, secretion, and vacuole fusion in fission yeast. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we isolated rho3(+, which encodes a Rho-family small GTPase, an important regulator of exocystosis, as a multicopy-suppressor of the temperature-sensitive growth of the apm1-1 mutant cells. Overexpression of Rho3 suppressed the Cl(- sensitivity and immunosuppressant sensitivity of the apm1-1 mutant cells. Overexpression of Rho3 also suppressed the fragmentation of vacuoles, and the accumulation of v-SNARE Syb1 in Golgi/endosomes and partially suppressed the defective secretion associated with apm1-deletion cells. Notably, electron microscopic observation of the rho3-deletion cells revealed the accumulation of abnormal Golgi-like structures, vacuole fragmentation, and accumulation of secretory vesicles; these phenotypes were very similar to those of the apm1-deletion cells. Furthermore, the rho3-deletion cells and apm1-deletion cells showed very similar phenotypic characteristics, including the sensitivity to the immunosuppressant FK506, the cell wall-damaging agent micafungin, Cl(-, and valproic acid. Green fluorescent protein (GFP-Rho3 was localized at Golgi/endosomes as well as the plasma membrane and division site. Finally, Rho3 was shown to form a complex with Apm1 as well as with other subunits of the clathrin-associated AP-1 complex in a GTP- and effector domain-dependent manner. CONCLUSIONS/SIGNIFICANCE: Taken together, our findings reveal a novel role of Rho3 in the regulation of Golgi/endosome trafficking and suggest that clathrin-associated adaptor protein-1 and Rho3 co-ordinate in intracellular transport in fission yeast. To the best of our knowledge, this study provides the first evidence

Shifted Golgi targeting of glycosyltransferases and α-mannosidase IA from giantin to GM130-GRASP65 results in formation of high mannose N-glycans in aggressive prostate cancer cells.

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Bhat, Ganapati; Hothpet, Vishwanath-Reddy; Lin, Ming-Fong; Cheng, Pi-Wan

2017-11-01

There is a pressing need for biomarkers that can distinguish indolent from aggressive prostate cancer to prevent over-treatment of patients with indolent tumor. Golgi targeting of glycosyltransferases was characterized by confocal microscopy after knockdown of GM130, giantin, or both. N-glycans on a trans-Golgi enzyme β4galactosyltransferase-1 isolated by immunoprecipitation from androgen-sensitive and independent prostate cancer cells were determined by matrix-assisted laser desorption-time of flight-mass spectrometry. In situ proximity ligation assay was employed to determine co-localization of (a) α-mannosidase IA, an enzyme required for processing Man 8 GlcNAc 2 down to Man 5 GlcNAc 2 to enable synthesis of complex-type N-glycans, with giantin, GM130, and GRASP65, and (b) trans-Golgi glycosyltransferases with high mannose N-glycans terminated with α3-mannose. Defective giantin in androgen-independent prostate cancer cells results in a shift of Golgi targeting of glycosyltransferases and α-mannosidase IA from giantin to GM130-GRASP65. Consequently, trans-Golgi enzymes and cell surface glycoproteins acquire high mannose N-glycans, which are absent in cells with functional giantin. In situ proximity ligation assays of co-localization of α-mannosidase IA with GM130 and GRASP65, and trans-Golgi glycosyltransferases with high mannose N-glycans are negative in androgen-sensitive LNCaP C-33 cells but positive in androgen-independent LNCaP C-81 and DU145 cells, and LNCaP C-33 cells devoid of giantin. In situ proximity ligation assays of Golgi localization of α-mannosidase IA at giantin versus GM130-GRASP65 site, and absence or presence of N-glycans terminated with α3-mannose on trans-Golgi glycosyltransferases may be useful for distinguishing indolent from aggressive prostate cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

STED Imaging of Golgi Dynamics with Cer-SiR: A Two-Component, Photostable, High-Density Lipid Probe for Live Cells.

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Erdmann, Roman S; Toomre, Derek; Schepartz, Alanna

2017-01-01

Long time-lapse super-resolution imaging in live cells requires a labeling strategy that combines a bright, photostable fluorophore with a high-density localization probe. Lipids are ideal high-density localization probes, as they are >100 times more abundant than most membrane-bound proteins and simultaneously demark the boundaries of cellular organelles. Here, we describe Cer-SiR, a two-component, high-density lipid probe that is exceptionally photostable. Cer-SiR is generated in cells via a bioorthogonal reaction of two components: a ceramide lipid tagged with trans-cyclooctene (Cer-TCO) and a reactive, photostable Si-rhodamine dye (SiR-Tz). These components assemble within the Golgi apparatus of live cells to form Cer-SiR. Cer-SiR is benign to cellular function, localizes within the Golgi at a high density, and is sufficiently photostable to enable visualization of Golgi structure and dynamics by 3D confocal or long time-lapse STED microscopy.

Correlation with neuropsychological assessment and SPM analysis of brain perfusion SPECT in patients with progressive supranuclear palsy

International Nuclear Information System (INIS)

Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Kim, Jae Woo

2004-01-01

Progressive supranuclear palsy (PSP) is a degenerative condition of unknown aetiology that produces an akinetic-rigid form of parkinsonism characterised by early falls, dementia and abnormalities of extraocular movements. The patterns of decreased regional cerebral blood flow and cognitive impairment in PSP compared with normal control have been insufficiently investigated and a limited number of studies have been performed. We evaluated clinical symptoms, functional neuroimaging study using Tc-99m HMPAO SPECT and neuropsychological profiles in patients with PSP. Eleven patients with PSP diagnosed by the clinical criteria of National Institute of Neurological Disorders and Stroke and the Society for PSP (NINDS-SPSP) (mean age: 70.5±5.6 years, educational period: 4.5±4.7 years) and age-matched 10 healthy control subjects (mean age: 68.1±4.5 years, educational period: 6.5±4.1 years) participated in this study were participated. All patients were given a neurologic examination, brain MRI and cerebral perfusion SPECT using Tc-99m HMPAO. We concomittently evaluated several cognitive profiles using the Seoul Neuropsychological Screening Battery. SPM analysis of the SPECT image showed significant perfusion deficits in the left inferior frontal gyrus, left caudate nucleus, left middle frontal gyrus and cingulate gyrus in the patients with PSP compared with age-matched healthy control (uncorrected p<0.01). On neuropsychological assessment, cognitive deficits on verbal and visual memory, word fluency and frontal executive functions were prominent in most patients with PSP compared with healthy control subjects. Our findings suggest that measurement of regional cerebral blood flow by perfusion SPECT and voxel-based SPM analysis with neuropsychological assessment are useful to understanding the correlation between perfusion deficits and abnormal cognitive profiles in patients with PSP

Correlation with neuropsychological assessment and SPM analysis of brain perfusion SPECT in patients with progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Kim, Jae Woo [School of Medicine, Dong-A University, Busan (Korea, Republic of)

2004-07-01

Progressive supranuclear palsy (PSP) is a degenerative condition of unknown aetiology that produces an akinetic-rigid form of parkinsonism characterised by early falls, dementia and abnormalities of extraocular movements. The patterns of decreased regional cerebral blood flow and cognitive impairment in PSP compared with normal control have been insufficiently investigated and a limited number of studies have been performed. We evaluated clinical symptoms, functional neuroimaging study using Tc-99m HMPAO SPECT and neuropsychological profiles in patients with PSP. Eleven patients with PSP diagnosed by the clinical criteria of National Institute of Neurological Disorders and Stroke and the Society for PSP (NINDS-SPSP) (mean age: 70.5{+-}5.6 years, educational period: 4.5{+-}4.7 years) and age-matched 10 healthy control subjects (mean age: 68.1{+-}4.5 years, educational period: 6.5{+-}4.1 years) participated in this study were participated. All patients were given a neurologic examination, brain MRI and cerebral perfusion SPECT using Tc-99m HMPAO. We concomittently evaluated several cognitive profiles using the Seoul Neuropsychological Screening Battery. SPM analysis of the SPECT image showed significant perfusion deficits in the left inferior frontal gyrus, left caudate nucleus, left middle frontal gyrus and cingulate gyrus in the patients with PSP compared with age-matched healthy control (uncorrected p<0.01). On neuropsychological assessment, cognitive deficits on verbal and visual memory, word fluency and frontal executive functions were prominent in most patients with PSP compared with healthy control subjects. Our findings suggest that measurement of regional cerebral blood flow by perfusion SPECT and voxel-based SPM analysis with neuropsychological assessment are useful to understanding the correlation between perfusion deficits and abnormal cognitive profiles in patients with PSP.

La belle indifférence revisited: a case report on progressive supranuclear palsy misdiagnosed as conversion disorder

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van Meerkerk-Aanen PJ

2017-08-01

Full Text Available Petra J van Meerkerk-Aanen,1 Lars de Vroege,1,2 David Khasho,1 Aziza Foruz,1 J Thies van Asseldonk,3 Christina M van der Feltz-Cornelis1,2 1Clinical Center of Excellence for Body, Mind, and Health, GGz Breburg, 2Department Tranzo, Tilburg School of Behavioral and Social Sciences, Tilburg University, 3Department of Neurology, Elisabeth Hospital, Tilburg, the Netherlands Background: Since the advent of computed tomography and magnetic resonance imaging scans, neurological disorders have less often been falsely labeled as conversion disorder (CD. However, misdiagnosis of a neurological disorder as CD still occurs, especially in cases with insidious onset. Misinterpretation of la belle indifférence may contribute to such misdiagnosis. Here, we describe a case of progressive supranuclear palsy/Richardson’s syndrome (PSPS misdiagnosed as a case of CD.Case: A 62-year-old woman consulted two different neurologists in 2012 because of falling spells since 2009 and was diagnosed with CD. She was referred to the Clinical Center of Excellence for Body, Mind, and Health for treatment of CD. After neurological examination, blood tests, and psychiatric examination, in which la belle indifférence and a history of incest were found, CD was confirmed. However, despite treatment for CD, the patient’s physical symptoms deteriorated over a year. After repeated physical and psychiatric examinations, neurocognitive assessment, and consultation with a third neurologist because of suspicion of neurological disease, the patient was diagnosed with PSPS.Conclusion: La belle indifférence may be a psychological sign in the context of CD, but it may also be an expression of lack of mimic due to Parkinsonism or of eye movement disorder in the context of neurological illness. A diagnosis of CD should not be considered definitive if no improvement occurs in terms of physical, mental, and cognitive symptoms despite appropriate therapy. In case of deterioration, neurological

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

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Hickey, W F; Stieber, A; Hogue-Angeletti, R; Gonatas, J; GOnatas, N K

1983-10-01

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.

Proton accumulation and ATPase activity in Golgi apparatus-enriched vesicles from rat liver

International Nuclear Information System (INIS)

Yeh, H.I.; van Rossum, G.D.

1991-01-01

We have studied the mechanism by which liver Golgi apparatus maintains the acidity of its contents, using a subcellular fraction from rat liver highly enriched in Golgi marker enzymes. Proton accumulation (measured by quenching of acridine-orange fluorescence) and anion-dependent ATPase were characterized and compared. Maximal ATPase and proton accumulation required ATP; GTP and other nucleotides gave 10% to 30% of maximal activity. Among anions, Cl- and Br- approximately doubled the activities; others were much less effective. Half-maximal increase of ATPase and H+ uptake required 55 mmol/L and 27 mmol/L Cl-, respectively. In predominantly chloride media, SCN- and NO3- markedly inhibited H+ uptake. Nitrate competitively inhibited both the chloride-dependent ATPase (apparent Ki 6 mmol/L) and proton uptake (apparent Ki 2 mmol/L). Nitrate and SCN- also inhibited uptake of 36Cl. Replacing K+ with Na+ had no effect on the initial rate of proton uptake but somewhat reduced the steady state attained. Replacement of K+ with NH4+ and choline reduced proton uptake without affecting ATPase. The ATPase and H+ uptake were supported equally well by Mg2+ or Mn2+. The ATPase was competitively inhibited by 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid (apparent Ki 39 mumol/L). Other agents inhibiting both H+ uptake and ATPase were N-ethylmaleimide, N,N'-dicyclohexylcarbodiimide, chlorpromazine, diethylstilbestrol, Zn2+, Co2+ and Cu2+. In the Cl- medium, accumulated protons were released by ionophores at the relative rates, monensin = nigericin greater than valinomycin greater than carbonyl cyanide mchlorophenylhydrazone; the last of these also reduced ATPase activity. In the absence of Cl-, monensin and valinomycin both stimulated the ATPase. These results show a close association between ATPase activity and acidification of liver Golgi vesicles

Morphometric golgi study of some cortical locations in wag/rij and aci rat strains

NARCIS (Netherlands)

Karpova, A.V.; Bikbaev, A.F.; Coenen, A.M.L.; Luijtelaar, E.L.J.M. van; Luijtelaar, E.L.J.M. van; Kuznetsova, G.D.; Coenen, A.M.L.; Chepurnov, S.A.

2004-01-01

The present study was aimed to investigate the neuronal organization of two neocortical frontal zones using a Golgi staining technique in genetic epileptic rats, WAG/Rij's. One cortical zone was a specific part of the somatosensory cortex, which was recently proposed to contain a cortical epileptic

The GTPase Rab43 Controls the Anterograde ER-Golgi Trafficking and Sorting of GPCRs

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Chunman Li

2017-10-01

Full Text Available G-protein-coupled receptors (GPCRs constitute the largest superfamily of cell-surface signaling proteins. However, mechanisms underlying their surface targeting and sorting are poorly understood. Here, we screen the Rab family of small GTPases in the surface transport of multiple GPCRs. We find that manipulation of Rab43 function significantly alters the surface presentation and signaling of all GPCRs studied without affecting non-GPCR membrane proteins. Rab43 specifically regulates the transport of nascent GPCRs from the endoplasmic reticulum (ER to the Golgi. More interestingly, Rab43 directly interacts with GPCRs in an activation-dependent fashion. The Rab43-binding domain identified in the receptors effectively converts non-GPCR membrane protein transport into a Rab43-dependent pathway. These data reveal a crucial role for Rab43 in anterograde ER-Golgi transport of nascent GPCRs, as well as the ER sorting of GPCR members by virtue of its ability to interact directly.

Therapeutic advances in multiple system atrophy and progressive supranuclear palsy.

Science.gov (United States)

Poewe, Werner; Mahlknecht, Philipp; Krismer, Florian

2015-09-15

Multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are relentlessly progressive neurodegenerative diseases leading to severe disability and ultimately death within less than 10 y. Despite increasing efforts in basic and clinical research, effective therapies for these atypical parkinsonian disorders are lacking. Although earlier small clinical studies in MSA and PSP mainly focused on symptomatic treatment, advances in the understanding of the molecular underpinnings of these diseases and in the search for biomarkers have paved the way for the first large and well-designed clinical trials aiming at disease modification. Targets of intervention in these trials have included α-synuclein inclusion pathology in the case of MSA and tau-related mechanisms in PSP. Since 2013, four large randomized, placebo-controlled, double-blind disease-modification trials have been completed and published, using rasagiline (MSA), rifampicin (MSA), tideglusib (PSP), or davunetide (PSP). All of these failed to demonstrate signal efficacy with regard to the primary outcome measures. In addition, two randomized, placebo-controlled, double-blind trials have studied the efficacy of droxidopa in the symptomatic treatment of neurogenic orthostatic hypotension, including patients with MSA, with positive results in one trial. This review summarizes the design and the outcomes of these and other smaller trials published since 2013 and attempts to highlight priority areas of future therapeutic research in MSA and PSP. © 2015 International Parkinson and Movement Disorder Society. © 2015 International Parkinson and Movement Disorder Society.

FMNL2 and -3 regulate Golgi architecture and anterograde transport downstream of Cdc42

DEFF Research Database (Denmark)

Kage, Frieda; Steffen, Anika; Ellinger, Adolf

2017-01-01

The Rho-family small GTPase Cdc42 localizes at plasma membrane and Golgi complex and aside from protrusion and migration operates in vesicle trafficking, endo- and exocytosis as well as establishment and/or maintenance of cell polarity. The formin family members FMNL2 and -3 are actin assembly fa...

Neck Vibration Proprioceptive Postural Response Intact in Progressive Supranuclear Palsy unlike Idiopathic Parkinson’s Disease

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Stefan Kammermeier

2017-12-01

Full Text Available Progressive supranuclear palsy (PSP and late-stage idiopathic Parkinson’s disease (IPD are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Postural responses to sensory anteroposterior tilt illusion by bilateral dorsal neck vibration were probed in both groups versus healthy controls on a static recording posture platform. Three distinct anteroposterior body mass excursion peaks (P1–P3 were observed. 18 IPD subjects exhibited well-known excessive response amplitudes, whereas 21 PSP subjects’ responses remained unaltered to 22 control subjects. Neither IPD nor PSP showed response latency deficits, despite brainstem degeneration especially in PSP. The observed response patterns suggest that PSP brainstem pathology might spare the involved proprioceptive pathways and implies viability of neck vibration for possible biofeedback and augmentation therapy in PSP postural instability.

MIDBRAIN CATECHOLAMINERGIC NEURONS CO-EXPRESS α-SYNUCLEIN AND TAU IN PROGRESSIVE SUPRANUCLEAR PALSY

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María Elena eErro Aguirre

2015-03-01

Full Text Available Objective: To analyze the frequency and distribution of α-synuclein deposits in progressive supranuclear palsy (PSP.Methods: The brains of 25 cases of pathologically confirmed PSP were evaluated with immunohistochemistry for α-synuclein and tau. Multiple immunofluorescent stains were applied to analyze the expression of tau and α-synuclein aggregates in catecholaminergic neurons. Patients’ clinical symptoms were retrospectively recorded. Results: Deposits α-synuclein in the form of typical Lewy bodies (LBs were only found in two PSP cases (8% that fulfilled the clinical subtype of PSP known as Richardson’s syndrome (RS. LBs were present in the locus ceruleus, substantia nigra pars compacta, basal forebrain, amygdala and cingulated cortex in a distribution mimicking that of Parkinson’s disease. Triple-immunolabeling revealed co-expression of α-synuclein and tau proteins in some tyrosine hydroxilase-positive neurons of the locus ceruleus and substantia nigra pars compacta.Conclusions: There is no apparent clinical correlation between the presence of LBs in PSP. Tau protein co-aggregate with α-synuclein in catecholaminergic neurons of PSP brains suggesting a synergistic interaction between the two proteins. This is in keeping with the current view of neurodegenerative disorders as ‘misfolded protein diseases’.

Retromer guides STxB and CD8-M6PR from early to recycling endosomes, EHD1 guides STxB from recycling endosome to Golgi

Science.gov (United States)

McKenzie, Jenna E.; Raisley, Brent; Zhou, Xin; Naslavsky, Naava; Taguchi, Tomohiko; Caplan, Steve; Sheff, David

2012-01-01

Retrograde trafficking transports proteins, lipids and toxins from the plasma membrane to the Golgi and ER. To reach the Golgi, these cargos must transit the endosomal system, consisting of early endosomes, recycling endosomes, late endosomes and lysosomes. All cargos pass through early endosomes, but may take different routes to the Golgi. Retromer dependent cargos bypass the late endosomes to reach the Golgi. We compared how two very different retromer dependent cargos negotiate the endosomal sorting system. Shiga toxin B, bound to the external layer of the plasma membrane, and chimeric CD8-Mannose-6-Phosphate Receptor, which is anchored via a transmembrane domain. Both appear to pass through the recycling endosome. Ablation of the recycling endosome diverted both of these cargos to an aberrant compartment and prevented them from reaching the Golgi. Once in the recycling endosome, Shiga toxin required EHD1 to traffic to the TGN, while the CD8-Mannose-6-Phosphate Receptor was not significantly dependent on EHD1. Knockdown of retromer components left cargo in the early endosomes, suggesting that it is required for retrograde exit from this compartment. This work establishes the recycling endosome as a required step in retrograde traffic of at least these two retromer dependent cargos. Along this pathway, retromer is associated with EE to recycling endosome traffic, while EHD1 is associated with recycling endosome to TGN traffic of STxB. PMID:22540229

The organization of the Golgi complex and microtubules in skeletal muscle is fiber type-dependent

DEFF Research Database (Denmark)

Ralston, E; Lu, Z; Ploug, Thorkil

1999-01-01

Skeletal muscle has a nonconventional Golgi complex (GC), the organization of which has been a subject of controversy in the past. We have now examined the distribution of the GC by immunofluorescence and immunogold electron microscopy in whole fibers from different rat muscles, both innervated a...

Plasma Membrane Targeting of Protocadherin 15 Is Regulated by the Golgi-Associated Chaperone Protein PIST

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Hongyun Nie

2016-01-01

Full Text Available Protocadherin 15 (PCDH15 is a core component of hair cell tip-links and crucial for proper function of inner ear hair cells. Mutations of PCDH15 gene cause syndromic and nonsyndromic hearing loss. At present, the regulatory mechanisms responsible for the intracellular transportation of PCDH15 largely remain unknown. Here we show that PIST, a Golgi-associated, PDZ domain-containing protein, interacts with PCDH15. The interaction is mediated by the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI of PCDH15. Through this interaction, PIST retains PCDH15 in the trans-Golgi network (TGN and reduces the membrane expression of PCDH15. We have previously showed that PIST regulates the membrane expression of another tip-link component, cadherin 23 (CDH23. Taken together, our finding suggests that PIST regulates the intracellular trafficking and membrane targeting of the tip-link proteins CDH23 and PCDH15.

Nucleocytoplasmic shuttling of STK16 (PKL12), a Golgi-resident serine/threonine kinase involved in VEGF expression regulation

International Nuclear Information System (INIS)

Guinea, Barbara; Ligos, Jose Manuel; Lain de Lera, Teresa; Martin-Caballero, Juan; Flores, Juana; Gonzalez de la Pena, Manuel; Garcia-Castro, Javier; Bernad, Antonio

2006-01-01

PKL12/STK16 protein is the first identified mammalian member of a ser/thr kinase subfamily that is conserved across several kingdoms, with a broad expression pattern in murine tissues and cell types. Endogenous STK16 subcellular localization was evaluated by indirect immunofluorescence in NIH/3T3 and NRK cells, demonstrating a Golgi-associated pattern that appears to be independent of signals provided by integrin pathways. When cells were treated with brefeldin A (BFA) or nocodazole, drugs that promote Golgi disorganization, we observed STK16 translocation to the nuclear compartment. Constitutive overexpression of this protein by retroviral vectors also promotes accumulation of STK16 in the nuclear compartment, as shown by subfractionation studies. A kinase-dead STK16 mutant (E202A) was used to demonstrate that both the Golgi association and the nuclear translocation capabilities seem to be independent of the STK16 kinase activity. In addition, we show that STK16 overexpression in several cell lines enhances their capacity to produce and secrete VEGF. To confirm these data in vivo, we injected tumor cells overexpressing STK16 into immunodeficient BALBc/SCID mice. HT1080-derived tumors overexpressing STK16 showed increased volume and number of blood vessels compared to controls. Altogether, these data concur with previous reports suggesting a potential role for STK16 as a transcriptional co-activator

Genetic linkage of autosomal dominant progressive supranuclear palsy to 1q31.1.

Science.gov (United States)

Ros, Raquel; Gómez Garre, Pilar; Hirano, Michio; Tai, Yen F; Ampuero, Israel; Vidal, Lídice; Rojo, Ana; Fontan, Aurora; Vazquez, Ana; Fanjul, Samira; Hernandez, Jaime; Cantarero, Susana; Hoenicka, Janet; Jones, Alison; Ahsan, R Laila; Pavese, Nicola; Piccini, Paola; Brooks, David J; Perez-Tur, Jordi; Nyggard, Torbjorn; de Yébenes, Justo G

2005-05-01

Progressive supranuclear palsy (PSP) is a disorder of unknown pathogenesis. Familial clusters of PSP have been reported related to mutations of protein tau. We report the linkage of a large Spanish family with typical autosomal dominant PSP to a new locus in chromosome 1. Four members of this family had typical PSP, confirmed by neuropathology in one case. At least five ancestors had similar disease. Other members of the family have incomplete phenotypes. The power of the linkage analysis was increased by detecting presymptomatic individuals with 18F-fluoro-dopa and 18F-deoxyglucose positron emission tomography. We screened the human genome with 340 polymorphic markers and we enriched the areas of interest with additional markers. The disease status was defined according to the clinical and positron emission tomography data. We excluded linkage to the tau gene in chromosome 17. PSP was linked, in this family, to one area of 3.4 cM in chromosome 1q31.1, with a maximal multipoint < OD score of +3.53. This area contains at least three genes, whose relevance in PSP is unknown. We expect to further define the gene responsible for PSP, which could help to understand the pathogenesis of this disease and to design effective treatment.

Role of the Conserved Ologomeric Golgi Complex in the Abnormalities of Glycoprotein Processing in Breast Cancer Cells

National Research Council Canada - National Science Library

Zolov, Sergey

2004-01-01

.... We propose that the COG3 protein plays one of the main roles in these processes. We utilized RNA interference assay to knockdown COG3p in HeLa cells to determine the effect of its depletion on Golgi proteins localization...

Ramón y Cajal erroneously identified as Camillo Golgi on a souvenir postage stamp.

Science.gov (United States)

Triarhou, Lazaros C; del Cerro, Manuel

2012-01-01

Focusing on a philatelic oddity that erringly identifies a picture of Santiago Ramón y Cajal as that of Camillo Golgi, this brief article examines official and unofficial stamp issues honoring the two great neuroanatomists, one from Spain and the other from Italy, who were early Nobel Prize winners in Physiology or Medicine.

Analysis of thick brain sections by obverse-reverse computer microscopy: application of a new, high clarity Golgi-Nissl stain.

Science.gov (United States)

Glaser, E M; Van der Loos, H

1981-08-01

Exceptionally clear Golgi-Nissl sections of 300 micron thickness have been morphometrically studied by light microscopy using oil immersion objectives. The clarity results from a new variation of a staining procedure that combines Golgi and Nissl images in one section. A viewing technique has been developed that permits a histologic preparation to be examined from its obverse (or normally viewed) side and its reverse (or under) side. The technique was designed for use with a computer microscope but can be employed with any light microscope whose stage position can be measured within 100 micron. Sections thicker than 300 micron can be studied dependent on the working distance of the objective lens, provided that the clarity of the material permits it.

Modulating Endoplasmic Reticulum-Golgi Cargo Receptors for Improving Secretion of Carrier-Fused Heterologous Proteins in the Filamentous Fungus Aspergillus oryzae

Science.gov (United States)

Hoang, Huy-Dung; Maruyama, Jun-ichi

2014-01-01

Filamentous fungi are excellent hosts for industrial protein production due to their superior secretory capacity; however, the yield of heterologous eukaryotic proteins is generally lower than that of fungal or endogenous proteins. Although activating protein folding machinery in the endoplasmic reticulum (ER) improves the yield, the importance of intracellular transport machinery for heterologous protein secretion is poorly understood. Here, using Aspergillus oryzae as a model filamentous fungus, we studied the involvement of two putative lectin-like cargo receptors, A. oryzae Vip36 (AoVip36) and AoEmp47, in the secretion of heterologous proteins expressed in fusion with the endogenous enzyme α-amylase as the carrier. Fluorescence microscopy revealed that mDsRed-tagged AoVip36 localized in the Golgi compartment, whereas AoEmp47 showed localization in both the ER and the Golgi compartment. Deletion of AoVip36 and AoEmp47 improved heterologous protein secretion, but only AoVip36 deletion had a negative effect on the secretion of α-amylase. Analysis of ER-enriched cell fractions revealed that AoVip36 and AoEmp47 were involved in the retention of heterologous proteins in the ER. However, the overexpression of each cargo receptor had a different effect on heterologous protein secretion: AoVip36 enhanced the secretion, whereas AoEmp47 promoted the intracellular retention. Taken together, our data suggest that AoVip36 and AoEmp47 hinder the secretion of heterologous proteins by promoting their retention in the ER but that AoVip36 also promotes the secretion of heterologous proteins. Moreover, we found that genetic deletion of these putative ER-Golgi cargo receptors significantly improves heterologous protein production. The present study is the first to propose that ER-Golgi transport is a bottleneck for heterologous protein production in filamentous fungi. PMID:25362068

Endogenous glycosphingolipid acceptor specificity of sialosyltransferase systems in intact golgi membranes, synaptosomes, and synaptic plasma membranes from rat brain

International Nuclear Information System (INIS)

Durrie, R.; Saito, M.; Rosenberg, A.

1988-01-01

Preparations highly enriched in Golgi complex membranes, synaptosomes, and synaptic plasma membranes (SPM) by marker enzyme analysis and electron microscopic morphology were made from the brains of 28-day-old rats. These were incubated with cytidine 5'-monophosphate-N-acetyl[ 14 C]neuraminic acid (CMP-NeuAc) in a physiologic buffer, without detergents. Glycolipid sialosyltransferase activities (SATs) were measured by analyzing incorporation of radiolabeled NeuAc into endogenous membrane gangliosides. Golgi SAT was diversified in producing all the various molecular species of labeled gangliosides. Synaptosomal SAT exhibited a lower activity, but it was highly specific in its labeling pattern, with a marked preference for labeling NeuAcα2 → 8NeuAcα2 → 3Galβ1 → 4Glcβ1 → 1Cer (GD3 ganglioside). SPM prepared from the synaptosomes retained the GD3-related SAT (or SAT-2), and the total specific activity increased, which suggests that the location of the synaptosomal activity is in the SPM. These results indicate that SAT activity in Golgi membranes differs from that in synaptosomes with regard to endogenous acceptor substrate specificity and SAT activity of synaptosomes should be located in the synaptosomal plasma membrane. This SAT could function as an ectoenzyme in concert with ecto-sialidase to modulate the GD3 and other ganglioside population in situ at the SPM of the central nervous system

Mutations in TRAPPC12 Manifest in Progressive Childhood Encephalopathy and Golgi Dysfunction.

Science.gov (United States)

Milev, Miroslav P; Grout, Megan E; Saint-Dic, Djenann; Cheng, Yong-Han Hank; Glass, Ian A; Hale, Christopher J; Hanna, David S; Dorschner, Michael O; Prematilake, Keshika; Shaag, Avraham; Elpeleg, Orly; Sacher, Michael; Doherty, Dan; Edvardson, Simon

2017-08-03

Progressive childhood encephalopathy is an etiologically heterogeneous condition characterized by progressive central nervous system dysfunction in association with a broad range of morbidity and mortality. The causes of encephalopathy can be either non-genetic or genetic. Identifying the genetic causes and dissecting the underlying mechanisms are critical to understanding brain development and improving treatments. Here, we report that variants in TRAPPC12 result in progressive childhood encephalopathy. Three individuals from two unrelated families have either a homozygous deleterious variant (c.145delG [p.Glu49Argfs ∗ 14]) or compound-heterozygous variants (c.360dupC [p.Glu121Argfs ∗ 7] and c.1880C>T [p. Ala627Val]). The clinical phenotypes of the three individuals are strikingly similar: severe disability, microcephaly, hearing loss, spasticity, and characteristic brain imaging findings. Fibroblasts derived from all three individuals showed a fragmented Golgi that could be rescued by expression of wild-type TRAPPC12. Protein transport from the endoplasmic reticulum to and through the Golgi was delayed. TRAPPC12 is a member of the TRAPP protein complex, which functions in membrane trafficking. Variants in several other genes encoding members of the TRAPP complex have been associated with overlapping clinical presentations, indicating shared and distinct functions for each complex member. Detailed understanding of the TRAPP-opathies will illuminate the role of membrane protein transport in human disease. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Abnormal Resting-State Functional Connectivity in Progressive Supranuclear Palsy and Corticobasal Syndrome

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Komal Bharti

2017-06-01

Full Text Available BackgroundPathological and MRI-based evidence suggests that multiple brain structures are likely to be involved in functional disconnection between brain areas. Few studies have investigated resting-state functional connectivity (rsFC in progressive supranuclear palsy (PSP and corticobasal syndrome (CBS. In this study, we investigated within- and between-network rsFC abnormalities in these two conditions.MethodsTwenty patients with PSP, 11 patients with CBS, and 16 healthy subjects (HS underwent a resting-state fMRI study. Resting-state networks (RSNs were extracted to evaluate within- and between-network rsFC using the Melodic and FSLNets software packages.ResultsIncreased within-network rsFC was observed in both PSP and CBS patients, with a larger number of RSNs being involved in CBS. Within-network cerebellar rsFC positively correlated with mini-mental state examination scores in patients with PSP. Compared to healthy volunteers, PSP and CBS patients exhibit reduced functional connectivity between the lateral visual and auditory RSNs, with PSP patients additionally showing lower functional connectivity between the cerebellar and insular RSNs. Moreover, rsFC between the salience and executive-control RSNs was increased in patients with CBS compared to HS.ConclusionThis study provides evidence of functional brain reorganization in both PSP and CBS. Increased within-network rsFC could represent a higher degree of synchronization in damaged brain areas, while between-network rsFC abnormalities may mainly reflect degeneration of long-range white matter fibers.

Abnormal cortical synaptic plasticity in primary motor area in progressive supranuclear palsy.

Science.gov (United States)

Conte, Antonella; Belvisi, Daniele; Bologna, Matteo; Ottaviani, Donatella; Fabbrini, Giovanni; Colosimo, Carlo; Williams, David R; Berardelli, Alfredo

2012-03-01

No study has yet investigated whether cortical plasticity in primary motor area (M1) is abnormal in patients with progressive supranuclear palsy (PSP). We studied M1 plasticity in 15 PSP patients and 15 age-matched healthy subjects. We used intermittent theta-burst stimulation (iTBS) to investigate long-term potentiation (LTP) and continuous TBS (cTBS) to investigate long-term depression (LTD)-like cortical plasticity in M1. Ten patients underwent iTBS again 1 year later. We also investigated short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) in M1 with paired-pulse transcranial magnetic stimulation, tested H reflex from upper limb flexor muscles before and after iTBS, and measured motor evoked potential (MEP) input-output (I/O) curves before and after iTBS. iTBS elicited a significantly larger MEP facilitation after iTBS in patients than in healthy subjects. Whereas in healthy subjects, cTBS inhibited MEP, in patients it significantly facilitated MEPs. In patients, SICI was reduced, whereas ICF was normal. H reflex size remained unchanged after iTBS. Patients had steeper MEP I/O slopes than healthy subjects at baseline and became even more steeper after iTBS only in patients. The iTBS-induced abnormal MEP facilitation in PSP persisted at 1-year follow-up. In conclusion, patients with PSP have abnormal M1 LTP/LTD-like plasticity. The enhanced LTP-like cortical synaptic plasticity parallels disease progression.

Golgi twins in late mitosis revealed by genetically encoded tags for live cell imaging and correlated electron microscopy

NARCIS (Netherlands)

Gaietta, Guido M; Giepmans, Ben N G; Deerinck, Thomas J; Smith, W Bryan; Ngan, Lucy; Llopis, Juan; Adams, Stephen R; Tsien, Roger Y; Ellisman, Mark H

2006-01-01

Combinations of molecular tags visible in light and electron microscopes become particularly advantageous in the analysis of dynamic cellular components like the Golgi apparatus. This organelle disassembles at the onset of mitosis and, after a sequence of poorly understood events, reassembles after

Significance of apparent diffusion coefficient measurement for the differential diagnosis of multiple system atrophy, progressive supranuclear palsy, and Parkinson's disease: evaluation by 3.0-T MR imaging

International Nuclear Information System (INIS)

Tsukamoto, Kazumichi; Kanasaki, Yoshiko; Kakite, Suguru; Fujii, Shinya; Kaminou, Toshio; Ogawa, Toshihide; Matsusue, Eiji

2012-01-01

The clinical differentiation of Parkinson's disease (PD) from multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) may be challenging, especially in their early stages. The aim of this study was to evaluate the utility of apparent diffusion coefficient (ADC) measurement to distinguish among these degenerative disorders. Twenty-five MSA, 20 PSP, and 17 PD patients and 18 healthy controls were retrospectively studied. Axial diffusion-weighted and T2-weighted images were obtained using a 3-T MR system. Regions of interest (ROIs) were precisely placed in the midbrain, pons, putamen, globus pallidus, caudate nucleus, thalamus, superior cerebellar peduncle, middle cerebellar peduncle, cerebellar white matter, and cerebellar dentate nucleus, and the regional ADC (rADC) value was calculated in each ROI. In MSA, rADC values in the pons, middle cerebellar peduncle, cerebellar white matter, and cerebellar dentate nucleus were significantly higher than in PSP, PD, and controls. Furthermore, rADC values in the posterior putamen were significantly higher in MSA than in PSP and controls. In PSP, rADC values were significantly higher in the globus pallidus and midbrain than in MSA, PD, and controls. Furthermore, rADC values in the caudate nucleus and superior cerebellar peduncle were significantly higher in PSP than in MSA and controls. In PD, there were no significant differences in the rADC values compared to in MSA, PSP, and controls in all regions. Evaluation of rADC values in characteristic lesions in MSA, PSP, and PD by placing ROIs using 3-T systems can provide useful additional information for differentiating these disorders. (orig.)

Golgi localized barley MTP8 proteins facilitate Mn transport

DEFF Research Database (Denmark)

Pedas, Pai Rosager; Schiller, Michaela; Hegelund, Josefine Nymark

2014-01-01

Many metabolic processes in plants are regulated by manganese (Mn) but limited information is available on the molecular mechanisms controlling cellular Mn homeostasis. In this study, a yeast assay was used to isolate and characterize two genes, MTP8.1 and MTP8.2 , which encode membrane...... in yeast, MTP8.1 and MTP8.2 were found to be Mn transporters catalysing Mn efflux in a similar manner as the Golgi localized endogenous yeast protein Pmr1p. The level of MTP8.1 transcripts in barley roots increased with external Mn supply ranging from deficiency to toxicity, while MTP8.2 transcripts...

Differential distribution of striatal [123I]β-CIT in Parkinson's disease and progressive supranuclear palsy, evaluated with single-photon emission tomography

International Nuclear Information System (INIS)

Messa, C.; Volonte, M.A.; Fazio, F.; Zito, F.; Carpinelli, A.; D'Amico, A.; Rizzo, G.; Moresco, R.M.; Paulesu, E.; Franceschi, M.; Lucignani, G.

1998-01-01

Functional imaging of the presynaptic dopaminergic activity using single-photon emission tomography (SPET) and iodine-123 labelled 2-β-carboxymethoxy-3-β-(4-iodophenyl)tropane ([ 123 I]β-CIT) is important for the assessment of disease severity and progression in patients with Parkinson's disease (PD). However, its capability to discriminate between different extrapyramidal disorders has not yet been assessed. The aim of this study was to evaluate the possibility of differentiating patients with PD and with progressive supranuclear palsy (PSP) by means of this method. The distribution of [ 123 I]β-CIT in the basal ganglia was assessed in six normal subjects, 13 petients with PD and five patients with PSP in whom the disease was mild. SPET images were obtained 24±2 h after i.v. injection of the tracer using a brain-dedicated system (CERASPECT). MR and SPET images were co-registered in four normal subjects and used to define a standard set of 16 circular regions of interest (ROIs) on the slice showing the highest striatal activity. The basal ganglia ROIs corresponded to (1) the head of caudate, (2) a region of transition between the head of caudate and the anterior putamen, (3) the anterior putamen and (4) the posterior putamen. A ratio of specific to non-displaceable striatal uptake was calculated normalising the activity of the basal ganglia ROIs to that of the occipital cortex (V3''). ANOVA revealed a global reduction of V3'' in all ROIs of PD and PSP patients compared with normal controls (P 123 I]β-CIT distribution in discrete striatal areas provides information on the relative caudate-putamen damage, with different values being obtained in patients clinically diagnosed as having either PD or PSP. (orig.)

Trafficking of human ADAM 12-L: retention in the trans-Golgi network

DEFF Research Database (Denmark)

Hougaard, S; Loechel, F; Xu, X

2000-01-01

We have investigated the trafficking of the membrane-anchored form of human ADAM 12 (ADAM 12-L) fused to a green fluorescence protein tag. Subcellular localization of the protein in transiently transfected cells was determined by fluorescence microscopy and trypsin sensitivity. Full-length ADAM 12...... the cytoplasmic and transmembrane domains, but not the Src homology 3 domain (SH3) binding sites. These results raise the possibility that a trafficking checkpoint in the trans-Golgi network is one of the cellular mechanisms for regulation of ADAM 12-L function, by allowing a rapid release of ADAM 12-L...

Function of the Golgi-located phosphate transporter PHT4;6 is critical for senescence-associated processes in Arabidopsis

Czech Academy of Sciences Publication Activity Database

Hassler, S.; Jung, B.; Lemke, L.; Novák, Ondřej; Strnad, Miroslav; Martinoia, E.; Neuhaus, H.E.

2016-01-01

Roč. 67, č. 15 (2016), s. 4671-4684 ISSN 0022-0957 R&D Projects: GA ČR GA15-22322S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : ammonium * cytokinin * golgi Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.830, year: 2016

Progressive supranuclear palsy dopamine D2 receptor tomoscintigraphy to detect L-dopamine efficiency. Paralysies supra-nucleaires progressives. Quantification des recepteurs dopaminergiques D2 par tomoscintigraphie

Energy Technology Data Exchange (ETDEWEB)

Tranquart, F; Henry Le Bras, F; Toffol, B de; Autret, A; Guilloteau, D; Baulieu, J L [Hopital Bretonneau, 37 - Tours (France)

1994-09-01

Progressive supranuclear palsy (PSP) may sometimes be misdiagnosed as Parkinson's disease in its early stages, hence an early positive diagnosis of PSP based on dopamine D2 receptor density could be extremely valuable. In the present case report, the absence of dopamine D2 receptors was clearly demonstrated in the striatum using [sup 123]I-iodobenzamide (IBZM) tomoscintigraphy. This illustrates the potential use of IBZM tomoscintigraphy to identify Parkinson-like's disease presenting with decreased dopamine D2 receptor density; and hence to predict L-Dopa effectiveness. Further studies are needed to evaluate the value of IBZM tomoscintigraphy in the different Parkinson's like diseases. (authors). 11 refs., 2 figs.

Orf virus interferes with MHC class I surface expression by targeting vesicular transport and Golgi

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Rohde Jörg

2012-07-01

Full Text Available Abstract Background The Orf virus (ORFV, a zoonotic Parapoxvirus, causes pustular skin lesions in small ruminants (goat and sheep. Intriguingly, ORFV can repeatedly infect its host, despite the induction of a specific immunity. These immune modulating and immune evading properties are still unexplained. Results Here, we describe that ORFV infection of permissive cells impairs the intracellular transport of MHC class I molecules (MHC I as a result of structural disruption and fragmentation of the Golgi apparatus. Depending on the duration of infection, we observed a pronounced co-localization of MHC I and COP-I vesicular structures as well as a reduction of MHC I surface expression of up to 50%. These subversion processes are associated with early ORFV gene expression and are accompanied by disturbed carbohydrate trimming of post-ER MHC I. The MHC I population remaining on the cell surface shows an extended half-life, an effect that might be partially controlled also by late ORFV genes. Conclusions The presented data demonstrate that ORFV down-regulates MHC I surface expression in infected cells by targeting the late vesicular export machinery and the structure and function of the Golgi apparatus, which might aid to escape cellular immune recognition.

TMEM199 Deficiency Is a Disorder of Golgi Homeostasis Characterized by Elevated Aminotransferases, Alkaline Phosphatase, and Cholesterol and Abnormal Glycosylation

NARCIS (Netherlands)

Jansen, Jos C.; Timal, Sharita; van Scherpenzeel, Monique; Michelakakis, Helen; Vicogne, Dorothée; Ashikov, Angel; Moraitou, Marina; Hoischen, Alexander; Huijben, Karin; Steenbergen, Gerry; van den Boogert, Marjolein A. W.; Porta, Francesco; Calvo, Pier Luigi; Mavrikou, Mersyni; Cenacchi, Giovanna; van den Bogaart, Geert; Salomon, Jody; Holleboom, Adriaan G.; Rodenburg, Richard J.; Drenth, Joost P. H.; Huynen, Martijn A.; Wevers, Ron A.; Morava, Eva; Foulquier, François; Veltman, Joris A.; Lefeber, Dirk J.

2016-01-01

Congenital disorders of glycosylation (CDGs) form a genetically and clinically heterogeneous group of diseases with aberrant protein glycosylation as a hallmark. A subgroup of CDGs can be attributed to disturbed Golgi homeostasis. However, identification of pathogenic variants is seriously

Retinal degeneration in progressive supranuclear palsy measured by optical coherence tomography and scanning laser polarimetry.

Science.gov (United States)

Stemplewitz, Birthe; Kromer, Robert; Vettorazzi, Eik; Hidding, Ute; Frings, Andreas; Buhmann, Carsten

2017-07-13

This cross-sectional study compared the retinal morphology between patients with progressive supranuclear palsy (PSP) and healthy controls. (The retinal nerve fiber layer (RNFL) around the optic disc and the retina in the macular area of 22 PSP patients and 151 controls were investigated by spectral domain optical coherence tomography (SD-OCT). Additionally, the RNFL and the nerve fiber index (NFI) were measured by scanning laser polarimetry (SLP). Results of RNFL measurements with SD-OCT and SLP were compared to assess diagnostic discriminatory power. Applying OCT, PSP patients showed a smaller RNFL thickness in the inferior nasal and inferior temporal areas. The macular volume and the thickness of the majority of macular sectors were reduced compared to controls. SLP data showed a thinner RNFL thickness and an increase in the NFI in PSP patients. Sensitivity and specificity to discriminate PSP patients from controls were higher applying SLP than SD-OCT. Retinal changes did not correlate with disease duration or severity in any OCT or SLP measurement. PSP seems to be associated with reduced thickness and volume of the macula and reduction of the RNFL, independent of disease duration or severity. Retinal imaging with SD-OCT and SLP might become an additional tool in PSP diagnosis.

ECA3, a Golgi-localized P_2A-type-ATPase, plays a crucial role in manganese nutrition in Arabidopsis

DEFF Research Database (Denmark)

Mills, Rebecca F.; Doherty, Melissa Louise; Lopez Marques, Rosa Laura

2008-01-01

and development, and transport processes play a key role in regulating their cellular levels. Arabidopsis (Arabidopsis thaliana) contains four P(2A)-type ATPase genes, AtECA1 to AtECA4, which are expressed in all major organs of Arabidopsis. To elucidate the physiological role of AtECA2 and AtECA3 in Arabidopsis...... not so striking because in this case all plants were severely affected. ECA3 partially restored the growth defect on high Mn of the yeast (Saccharomyces cerevisiae) pmr1 mutant, which is defective in a Golgi Ca/Mn pump (PMR1), and the yeast K616 mutant (Deltapmc1 Deltapmr1 Deltacnb1), defective in Golgi...

Rehabilitation in progressive supranuclear palsy: Effectiveness of two multidisciplinary treatments.

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Ilaria Clerici

Full Text Available to date, there are no medical or surgical treatments for progressive supranuclear palsy (PSP. It is possible to speculate that patients with PSP could benefit from rehabilitative treatments designed for Parkinson's disease, including the use of robot-assisted walking training.to evaluate whether the use of the robotic device Lokomat® is superior in PSP patients to the use of treadmill with visual cues and auditory feedbacks (treadmill-plus in the context of an aerobic, multidisciplinary, intensive, motor-cognitive and goal-based rehabilitation treatment (MIRT conceived for Parkinsonian patients.we enrolled twenty-four PSP patients. Twelve subjects underwent a 4-week MIRT exploiting the use of the treadmill-plus (MIRT group. Twelve subjects underwent the same treatment, but replacing the treadmill-plus with Lokomat® (MIRT-Lokomat group. Subjects were evaluated with clinical and functional scales at admission and discharge. The primary outcomes were the total PSP Rating Scale (PSPRS score and its "limb" and "gait" sub-scores. Secondary outcomes were Berg Balance Scale (BBS, Six Minutes Walking test (6MWT and the number of falls.total PSPRS, PSPRS-gait sub-score, BBS, 6MWT and number of falls improved significantly in both groups (p ≤ 0.003 all, except 6MWT, p = 0.032 and p = 0.018 in MIRT-Lokomat and MIRT group respectively. The PSPRS-limb sub-score improved significantly only in the MIRT group (p = 0.002. A significant difference between groups was observed only for total PSPRS, indicating a slightly better improvement for patients in the MIRT group (p = 0.047. No differences between groups were revealed for the other outcomes, indicating that the effect of rehabilitation was similar in both groups.Lokomat® training, in comparison with treadmill-plus training, does not provide further benefits in PSP patients undergoing MIRT. Our findings suggest the usefulness of an aerobic, multidisciplinary, intensive, motor-cognitive and goal

Structural Basis for the Interaction of the Golgi-Associated Retrograde Protein (GARP) Complex with the t-SNARE Syntaxin 6

Science.gov (United States)

Abascal-Palacios, Guillermo; Schindler, Christina; Rojas, Adriana L; Bonifacino, Juan S.; Hierro, Aitor

2016-01-01

Summary The Golgi-Associated Retrograde Protein (GARP) is a tethering complex involved in the fusion of endosome-derived transport vesicles to the trans-Golgi network through interaction with components of the Syntaxin 6/Syntaxin 16/Vti1a/VAMP4 SNARE complex. The mechanisms by which GARP and other tethering factors engage the SNARE fusion machinery are poorly understood. Herein we report the structural basis for the interaction of the human Ang2 subunit of GARP with Syntaxin 6 and the closely related Syntaxin 10. The crystal structure of Syntaxin 6 Habc domain in complex with a peptide from the N terminus of Ang2 shows a novel binding mode in which a di-tyrosine motif of Ang2 interacts with a highly conserved groove in Syntaxin 6. Structure-based mutational analyses validate the crystal structure and support the phylogenetic conservation of this interaction. The same binding determinants are found in other tethering proteins and syntaxins, suggesting a general interaction mechanism. PMID:23932592

Association of the golgi UDP-galactose transporter with UDP-galactose: ceramide galactosyltransferase allows UDP-galactose import in the endoplasmic reticulum

NARCIS (Netherlands)

Sprong, H.; Degroote, S.; Nilsson, T.; Kawakita, M.; Ishida, N.; van der Sluijs, P.; van Meer, G.

2003-01-01

UDP-galactose reaches the Golgi lumen through the UDP-galactose transporter (UGT) and is used for the galactosylation of proteins and lipids. Ceramides and diglycerides are galactosylated within the endoplasmic reticulum by the UDP-galactose: ceramide galactosyltransferase. It is not known how

Identification of rice cornichon as a possible cargo receptor for the Golgi-localized sodium transporter OsHKT1;3

Czech Academy of Sciences Publication Activity Database

Rosas-Santiago, P.; Lagunas-Goméz, D.; Barkla, B. J.; Vera-Estrella, R.; Lalonde, S.; Jones, A.; Frommer, W. B.; Zimmermannová, Olga; Sychrová, Hana; Pantoja, O.

2015-01-01

Roč. 66, č. 9 (2015), s. 2733-2748 ISSN 0022-0957 R&D Projects: GA MŠk(CZ) LD13037 Institutional support: RVO:67985823 Keywords : Cornichon * endoplasmic reticulum * Golgi * OsHKT1-3 * protein–protein interaction Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.677, year: 2015

GOLGA2/GM130, cis-Golgi Matrix Protein, is a Novel Target of Anticancer Gene Therapy

OpenAIRE

Chang, Seung-Hee; Hong, Seong-Ho; Jiang, Hu-Lin; Minai-Tehrani, Arash; Yu, Kyeong-Nam; Lee, Jae-Ho; Kim, Ji-Eun; Shin, Ji-Young; Kang, Bitna; Park, Sungjin; Han, Kiwon; Chae, Chanhee; Cho, Myung-Haing

2012-01-01

Achievement of long-term survival of patients with lung cancer treated with conventional chemotherapy is still difficult for treatment of metastatic and advanced tumors. Despite recent progress in investigational therapies, survival rates are still disappointingly low and novel adjuvant and systemic therapies are urgently needed. A recently elucidated secretory pathway is attracting considerable interest as a promising anticancer target. The cis-Golgi matrix protein, GOLGA2/GM130, plays an im...

Phosphorylation in the C-terminal domain of Aquaporin-4 is required for Golgi transition in primary cultured astrocytes

International Nuclear Information System (INIS)

Kadohira, Ikuko; Abe, Yoichiro; Nuriya, Mutsuo; Sano, Kazumi; Tsuji, Shoji; Arimitsu, Takeshi; Yoshimura, Yasunori; Yasui, Masato

2008-01-01

Aquaporin-4 (AQP4) is expressed in the perivascular and subpial astrocytes end-feet in mammalian brain, and plays a critical component of an integrated water and potassium homeostasis. Here we examine whether AQP4 is phosphorylated in primary cultured mouse astrocytes. Astrocytes were metabolically labeled with [ 32 P]phosphoric acid, then AQP4 was immunoprecipitated with anti-AQP4 antibody. We observed that AQP4 was constitutively phosphorylated, which is reduced by treatment with protein kinase CK2 inhibitors. To elucidate the phosphorylation of AQP4 by CK2, myc-tagged wild-type or mutant AQP4 was transiently transfected in primary cultured astrocytes. Substitution of Ala residues for four putative CK2 phosphorylation sites in the C terminus abolished the phosphorylation of AQP4. Immunofluorescent microscopy revealed that the quadruple mutant was localized in the Golgi apparatus. These observations indicate that the C-terminal domain of AQP4 is constitutively phosphorylated at least in part by protein kinase CK2 and it is required for Golgi transition.

The Disturbance of Gaze in Progressive Supranuclear Palsy (PSP: Implications for Pathogenesis

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Athena L Chen

2010-12-01

Full Text Available Progressive supranuclear palsy (PSP is a disease of later life that is currently regarded as a form of neurodegenerative tauopathy. Disturbance of gaze is a cardinal clinical feature of PSP that often helps clinicians to establish the diagnosis. Since the neurobiology of gaze control is now well understood, it is possible to use eye movements as investigational tools to understand aspects of the pathogenesis of PSP. In this review, we summarize each disorder of gaze control that occurs in PSP, drawing on our studies of fifty patients, and on reports from other laboratories that have measured the disturbances of eye movements. When these gaze disorders are approached by considering each functional class of eye movements and its neurobiological basis, a distinct pattern of eye movement deficits emerges that provides insight into the pathogenesis of PSP. Although some aspects of all forms of eye movements are affected in PSP, the predominant defects concern vertical saccades (slow and hypometric, both up and down, impaired vergence, and inability to modulate the linear vestibulo-ocular reflex appropriately for viewing distance. These vertical and vergence eye movements habitually work in concert to enable visuomotor skills that are important during locomotion with the hands free. Taken with the prominent early feature of falls, these findings suggest that PSP tauopathy impairs a recently-evolved neural system concerned with bipedal locomotion in an erect posture and frequent gaze shifts between the distant environment and proximate hands. This approach provides a conceptual framework that can be used to address the nosological challenge posed by overlapping clinical and neuropathological features of neurodegenerative tauopathies.

Identification by [{sup 99m}Tc]ECD SPECT of anterior cingulate hypoperfusion in progressive supranuclear palsy, in comparison with Parkinson's disease

Energy Technology Data Exchange (ETDEWEB)

Varrone, Andrea [University Federico II, Biostructure and Bioimaging Institute, National Research Council/Department of Biomorphological and Functional Sciences, Napoli (Italy); Karolinska Hospital, Department of Clinical Neuroscience, Psychiatry Section, Stockholm (Sweden); Pagani, Marco; Salmaso, Dario [National Research Council, Institute of Cognitive Sciences and Technologies, Rome and Padua (Italy); Salvatore, Elena; Amboni, Marianna; De Michele, Giuseppe; Filla, Alessandro; Barone, Paolo [University Federico II, Department of Neurological Sciences, Napoli (Italy); Sansone, Valeria; Pappata, Sabina; Salvatore, Marco [University Federico II, Biostructure and Bioimaging Institute, National Research Council/Department of Biomorphological and Functional Sciences, Napoli (Italy); Nobili, Flavio [University of Genoa, Clinical Neurophysiology, Department of Endocrinological and Metabolic Sciences, Genoa (Italy)

2007-07-15

Progressive supranuclear palsy (PSP) is an akinetic-rigid syndrome that can be difficult to differentiate from Parkinson's disease (PD), particularly at an early stage. [{sup 99m}Tc]ethyl cysteinate dimer (ECD) SPECT could represent a widely available tool to assist in the differential diagnosis. In this study we used voxel-based analysis and Computerised Brain Atlas (CBA)-based principal component analysis (PCA) of [{sup 99m}Tc]ECD SPECT data to test whether: (1) specific patterns of rCBF abnormalities can differentiate PSP from controls and PD; (2) networks of dysfunctional brain regions can be found in PSP vs controls and PD. Nine PD patients, 16 PSP patients and ten controls were studied with [{sup 99m}Tc]ECD SPECT using a brain-dedicated device (Ceraspect). Voxel-based analysis was performed with statistical parametric mapping. PCA was applied to volume of interest data after spatial normalisation to CBA. The voxel-based analysis showed hypoperfusion of the anterior cingulate and medial frontal cortex in PSP compared with controls and PD. In PSP patients the rCBF impairment extended to the pre-supplementary motor area and prefrontal cortex, areas involved in executive function and motor networks. Compared with PSP patients, PD patients showed a mild rCBF decrease in associative visual areas which could be related to the known impairment of visuospatial function. The PCA identified three principal components differentiating PSP patients from controls and/or PD patients that included groups of cortical and subcortical brain regions with relatively decreased (cingulate cortex, prefrontal cortex and caudate) or increased (parietal cortex) rCBF, representing distinct functional networks in PSP. Anterior cingulate hypoperfusion seems to be an early, distinct brain abnormality in PSP as compared with PD. (orig.)

[18F]-THK5351 PET Correlates with Topology and Symptom Severity in Progressive Supranuclear Palsy

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Matthias Brendel

2018-01-01

Full Text Available Progressive supranuclear palsy (PSP is a neurodegenerative movement disorder characterized by deposition of fibrillar aggregates of 4R tau-protein in neurons and glial cells of the brain. These deposits are a key neuropathological finding, allowing a diagnosis of “definite PSP,” which is usually established post mortem. To date criteria for clinical diagnosis of PSP in vivo do not include biomarkers of tau pathology. For intervention trials, it is increasingly important to (i establish biomarkers for an early diagnosis and (ii to develop biomarkers that correlate with disease progression of PSP. [18F]-THK5351 is a novel PET-ligand that may afford in vivo visualization and quantification of tau-related alterations. We investigated binding characteristics of [18F]-THK5351 in patients with clinically diagnosed PSP and correlate tracer uptake with clinical findings. Eleven patients (68.4 ± 7.4 year; N = 6 female with probable PSP according to current clinical criteria and nine healthy controls (71.7 ± 7.2 year; N = 4 female underwent [18F]-THK5351 PET scanning. Voxel-wise statistical parametric comparison and volume-of-interest based quantification of standardized-uptake-values (SUV were conducted using the cerebellar cortex as reference region. We correlated disease severity as measured with the help of the PSP Rating Scale (PSPRS as well as several other clinical parameters with the individual PET findings. By voxel-wise mapping of [18F]-THK5351 uptake in the patient group we delineated typical distribution patterns that fit to known tau topology for PSP post mortem. Quantitative analysis indicated the strongest discrimination between PSP patients and healthy controls based on tracer uptake in the midbrain (+35%; p = 3.01E-7; Cohen's d: 4.0, followed by the globus pallidus, frontal cortex, and medulla oblongata. Midbrain [18F]-THK5351 uptake correlated well with clinical severity as measured by PSPRS (R = 0.66; p = 0.026. OCT and MRI

Genetic, structural, and chemical insights into the dual function of GRASP55 in germ cell Golgi remodeling and JAM-C polarized localization during spermatogenesis.

Directory of Open Access Journals (Sweden)

Amandine Cartier-Michaud

2017-06-01

Full Text Available Spermatogenesis is a dynamic process that is regulated by adhesive interactions between germ and Sertoli cells. Germ cells express the Junctional Adhesion Molecule-C (JAM-C, encoded by Jam3, which localizes to germ/Sertoli cell contacts. JAM-C is involved in germ cell polarity and acrosome formation. Using a proteomic approach, we demonstrated that JAM-C interacted with the Golgi reassembly stacking protein of 55 kDa (GRASP55, encoded by Gorasp2 in developing germ cells. Generation and study of Gorasp2-/- mice revealed that knock-out mice suffered from spermatogenesis defects. Acrosome formation and polarized localization of JAM-C in spermatids were altered in Gorasp2-/- mice. In addition, Golgi morphology of spermatocytes was disturbed in Gorasp2-/- mice. Crystal structures of GRASP55 in complex with JAM-C or JAM-B revealed that GRASP55 interacted via PDZ-mediated interactions with JAMs and induced a conformational change in GRASP55 with respect of its free conformation. An in silico pharmacophore approach identified a chemical compound called Graspin that inhibited PDZ-mediated interactions of GRASP55 with JAMs. Treatment of mice with Graspin hampered the polarized localization of JAM-C in spermatids, induced the premature release of spermatids and affected the Golgi morphology of meiotic spermatocytes.

Narcolepsy, REM sleep behavior disorder, and supranuclear gaze palsy associated with Ma1 and Ma2 antibodies and tonsillar carcinoma.

Science.gov (United States)

Adams, Chris; McKeon, Andrew; Silber, Michael H; Kumar, Rajeev

2011-04-01

To describe a patient with diencephalic and mesencephalic presentation of a Ma1 and Ma2 antibody-associated paraneoplastic neurological disorder. Case report. The Colorado Neurological Institute Movement Disorders Center in Englewood, Colorado, and the Mayo Clinic in Rochester, Minnesota. A 55-year-old man with a paraneoplastic neurological disorder characterized by rapid eye movement sleep behavior disorder, narcolepsy, and a progressive supranuclear palsy-like syndrome in the setting of tonsillar carcinoma. Immunotherapy for paraneoplastic neurological disorder, surgery and radiotherapy for cancer, and symptomatic treatment for parkinsonism and sleep disorders. Polysomnography, multiple sleep latency test, and neurological examination. The cancer was detected at a limited stage and treatable. After oncological therapy and immunotherapy, symptoms stabilized. Treatment with modafinil improved daytime somnolence. Rapid onset and progression of multifocal deficits may be a clue to paraneoplastic etiology. Early treatment of a limited stage cancer (with or without immunotherapy) may possibly slow progression of neurological symptoms. Symptomatic treatment may be beneficial.

Postural Stabilization Differences in Idiopathic Parkinson’s Disease and Progressive Supranuclear Palsy during Self-Triggered Fast Forward Weight Lifting

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Stefan Kammermeier

2018-01-01

Full Text Available Progressive supranuclear palsy (PSP and late-stage idiopathic Parkinson’s disease (IPD are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Self-triggered, weighted movements appear to provoke falls in IPD, but not in PSP. Repeated self-triggered lifting of a 0.5–1-kg weight (<2% of body weight with the dominant hand was performed in 17 PSP, 15 IPD with falling history, and 16 controls on a posturography platform. PSP showed excessive force scaling of weight and body motion with high-frequency multiaxial body sway, whereas IPD presented a delayed-onset forward body displacement. Differences in center of mass displacement apparent at very small weights indicate that both syndromes decompensate postural control already within stability limits. PSP may be subject to specific postural system devolution. IPD are susceptible to delayed forward falling. Differential physiotherapy strategies are suggested.

Functional genomics indicates yeast requires Golgi/ER transport, chromatin remodeling, and DNA repair for low dose DMSO tolerance

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Brandon David Gaytán

2013-08-01

Full Text Available Dimethyl sulfoxide (DMSO is frequently utilized as a solvent in toxicological and pharmaceutical investigations. It is therefore important to establish the cellular and molecular targets of DMSO in order to differentiate its intrinsic effects from those elicited by a compound of interest. We performed a genome-wide functional screen in Saccharomyces cerevisiae to identify deletion mutants exhibiting sensitivity to 1% DMSO, a concentration standard to yeast chemical profiling studies. We report that mutants defective in Golgi/ER transport are sensitive to DMSO, including those lacking components of the conserved oligomeric Golgi (COG complex. Moreover, strains deleted for members of the SWR1 histone exchange complex are hypersensitive to DMSO, with additional chromatin remodeling mutants displaying a range of growth defects. We also identify DNA repair genes important for DMSO tolerance. Finally, we demonstrate that overexpression of histone H2A.Z, which replaces chromatin-associated histone H2A in a SWR1-catalyzed reaction, confers resistance to DMSO. Many yeast genes described in this study have homologs in more complex organisms, and the data provided is applicable to future investigations into the cellular and molecular mechanisms of DMSO toxicity.

Progressive Supranuclear Palsy and Corticobasal Degeneration: Pathophysiology and Treatment Options.

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Lamb, Ruth; Rohrer, Jonathan D; Lees, Andrew J; Morris, Huw R

2016-09-01

There are currently no disease-modifying treatments for progressive supranuclear palsy (PSP) or corticobasal degeneration (CBD), and no approved pharmacological or therapeutic treatments that are effective in controlling their symptoms. The use of most pharmacological treatment options are based on experience in other disorders or from non-randomized historical controls, case series, or expert opinion. Levodopa may provide some improvement in symptoms of Parkinsonism (specifically bradykinesia and rigidity) in PSP and CBD; however, evidence is conflicting and where present, benefits are often negligible and short lived. In fact, "poor" response to levodopa forms part of the NINDS-SPSP criteria for the diagnosis of PSP and consensus criteria for the diagnosis of CBD (Lang Mov Disord. 20 Suppl 1:S83-91, 2005; Litvan et al. Neurology. 48:119-25, 1997; Armstrong et al. Neurology. 80(5):496-503, 2013). There is some evidence that intrasalivery gland botulinum toxin is useful in managing problematic sialorrhea and that intramuscular botulinum toxin and baclofen are helpful in reducing dystonia, including blepharospasm. Benzodiazepines may also be useful in managing dystonia. Myoclonus may be managed using levetiracetam and benzodiazepines. Pharmacological agents licensed for Alzheimer's disease (such as acetylcholinesterase inhibitors and N-Methyl-D-aspartate receptor antagonists) have been used off-label in PSP, CBD, and other tauopathies with the aim of improving cognition; however, there is limited evidence that they are effective and risk of adverse effects may outweigh benefits. The use of atypical antipsychotics for behavioural symptoms is not recommended in the elderly or those with demetia associated conditions and most antipsychotics will worsen Parkinsonism. Antidepressants may be useful for behavioral symptoms and depression but are often poorly tolerated due to adverse effects. In the absence of an effective drug treatment to target the underlying cause of

Cerebral blood flow SPECT may be helpful in establishing the diagnosis of progressive supranuclear palsy and corticobasal degeneration

International Nuclear Information System (INIS)

Slawek, J.; Lass, P.; Derejko, M.; Dubaniewicz, M.

2001-01-01

We present 4 cases, which illustrate the usefulness of neuroimaging studies in atypical forms of Parkinsonism. Progressive Supranuclear Palsy (PSP) and Corticobasal Degeneration (CBD) are rare neurodegenerative progressive disorders of the central nervous system of unknown cause. The clinical accuracy in this diagnosis is not very high even in centres specialising in movement disorders. Functional imaging can be helpful in diagnosing PSP and CBD. We present the results of cerebral blood flow (CBF) SPECT scanning in 2 patients with PSP and 2 patients with CBD. This was performed using a triple-head gammacamera and 99m Tc-HMPAO. In PSP patients a diffuse frontal perfusion deficit was seen, eventually with striatal and occipital hypoperfusion. CT/MRI was either normal or showed a diffuse cortical-subcortical atrophy. In CBD patients left fronto-parieto-temporal cortex and a striatal hypoperfusion were shown. CT scanning was normal in one case and showed an asymmetrical temporo-parietal atrophy in second one. The pattern of diffuse frontal perfusions deficit in PSP and asymmetrical, contralateral to symptoms of CBD, cortico-subcortical hypoperfusion may be helpful in establishing the correct diagnosis. (author)

Alternative promoter usage generates novel shorter MAPT mRNA transcripts in Alzheimer's disease and progressive supranuclear palsy brains.

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Huin, Vincent; Buée, Luc; Behal, Hélène; Labreuche, Julien; Sablonnière, Bernard; Dhaenens, Claire-Marie

2017-10-03

Alternative promoter usage is an important mechanism for transcriptome diversity and the regulation of gene expression. Indeed, this alternative usage may influence tissue/subcellular specificity, protein translation and function of the proteins. The existence of an alternative promoter for MAPT gene was considered for a long time to explain differential tissue specificity and differential response to transcription and growth factors between mRNA transcripts. The alternative promoter usage could explain partly the different tau proteins expression patterns observed in tauopathies. Here, we report on our discovery of a functional alternative promoter for MAPT, located upstream of the gene's second exon (exon 1). By analyzing genome databases and brain tissue from control individuals and patients with Alzheimer's disease or progressive supranuclear palsy, we identified novel shorter transcripts derived from this alternative promoter. These transcripts are increased in patients' brain tissue as assessed by 5'RACE-PCR and qPCR. We suggest that these new MAPT isoforms can be translated into normal or amino-terminal-truncated tau proteins. We further suggest that activation of MAPT's alternative promoter under pathological conditions leads to the production of truncated proteins, changes in protein localization and function, and thus neurodegeneration.

Regulation of cytokine receptors by Golgi N-glycan processing and endocytosis.

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Partridge, Emily A; Le Roy, Christine; Di Guglielmo, Gianni M; Pawling, Judy; Cheung, Pam; Granovsky, Maria; Nabi, Ivan R; Wrana, Jeffrey L; Dennis, James W

2004-10-01

The Golgi enzyme beta1,6 N-acetylglucosaminyltransferase V (Mgat5) is up-regulated in carcinomas and promotes the substitution of N-glycan with poly N-acetyllactosamine, the preferred ligand for galectin-3 (Gal-3). Here, we report that expression of Mgat5 sensitized mouse cells to multiple cytokines. Gal-3 cross-linked Mgat5-modified N-glycans on epidermal growth factor and transforming growth factor-beta receptors at the cell surface and delayed their removal by constitutive endocytosis. Mgat5 expression in mammary carcinoma was rate limiting for cytokine signaling and consequently for epithelial-mesenchymal transition, cell motility, and tumor metastasis. Mgat5 also promoted cytokine-mediated leukocyte signaling, phagocytosis, and extravasation in vivo. Thus, conditional regulation of N-glycan processing drives synchronous modification of cytokine receptors, which balances their surface retention against loss via endocytosis.

Cell wall accumulation of fluorescent proteins derived from a trans-Golgi cisternal membrane marker and paramural bodies in interdigitated Arabidopsis leaf epidermal cells.

Science.gov (United States)

Akita, Kae; Kobayashi, Megumi; Sato, Mayuko; Kutsuna, Natsumaro; Ueda, Takashi; Toyooka, Kiminori; Nagata, Noriko; Hasezawa, Seiichiro; Higaki, Takumi

2017-01-01

In most dicotyledonous plants, leaf epidermal pavement cells develop jigsaw puzzle-like shapes during cell expansion. The rapid growth and complicated cell shape of pavement cells is suggested to be achieved by targeted exocytosis that is coordinated with cytoskeletal rearrangement to provide plasma membrane and/or cell wall materials for lobe development during their morphogenesis. Therefore, visualization of membrane trafficking in leaf pavement cells should contribute an understanding of the mechanism of plant cell morphogenesis. To reveal membrane trafficking in pavement cells, we observed monomeric red fluorescent protein-tagged rat sialyl transferases, which are markers of trans-Golgi cisternal membranes, in the leaf epidermis of Arabidopsis thaliana. Quantitative fluorescence imaging techniques and immunoelectron microscopic observations revealed that accumulation of the red fluorescent protein occurred mostly in the curved regions of pavement cell borders and guard cell ends during leaf expansion. Transmission electron microscopy observations revealed that apoplastic vesicular membrane structures called paramural bodies were more frequent beneath the curved cell wall regions of interdigitated pavement cells and guard cell ends in young leaf epidermis. In addition, pharmacological studies showed that perturbations in membrane trafficking resulted in simple cell shapes. These results suggested possible heterogeneity of the curved regions of plasma membranes, implying a relationship with pavement cell morphogenesis.

Identification and functional analysis of two Golgi-localized UDP-galactofuranose transporters with overlapping functions in Aspergillus niger.

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Park, Joohae; Tefsen, Boris; Heemskerk, Marc J; Lagendijk, Ellen L; van den Hondel, Cees A M J J; van Die, Irma; Ram, Arthur F J

2015-11-02

Galactofuranose (Galf)-containing glycoconjugates are present in numerous microbes, including filamentous fungi where they are important for morphology, virulence and maintaining cell wall integrity. The incorporation of Galf-residues into galactomannan, galactomannoproteins and glycolipids is carried out by Golgi-localized Galf transferases. The nucleotide sugar donor used by these transferases (UDP-Galf) is produced in the cytoplasm and has to be transported to the lumen of the Golgi by a dedicated nucleotide sugar transporter. Based on homology with recently identified UDP-Galf-transporters in A. fumigatus and A. nidulans, two putative UDP-Galf-transporters in A. niger were found. Their function and localization was determined by gene deletions and GFP-tagging studies, respectively. The two putative UDP-Galf-transporters in A. niger are homologous to each other and are predicted to contain eleven transmembrane domains (UgtA) or ten transmembrane domains (UgtB) due to a reduced length of the C-terminal part of the UgtB protein. The presence of two putative UDP-Galf-transporters in the genome was not unique for A. niger. From the twenty Aspergillus species analysed, nine species contained two additional putative UDP-Galf-transporters. Three of the nine species were outside the Aspergillus section nigri, indication an early duplication of UDP-Galf-transporters and subsequent loss of the UgtB copy in several aspergilli. Deletion analysis of the single and double mutants in A. niger indicated that the two putative UDP-Galf-transporters (named UgtA and UgtB) have a redundant function in UDP-Galf-transport as only the double mutant displayed a Galf-negative phenotype. The Galf-negative phenotype of the double mutant could be complemented by expressing either CFP-UgtA or CFP-UgtB fusion proteins from their endogenous promoters, indicating that both CFP-tagged proteins are functional. Both Ugt proteins co-localize with each other as well as with the GDP

Force estimation from ensembles of Golgi tendon organs

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Mileusnic, M. P.; Loeb, G. E.

2009-06-01

Golgi tendon organs (GTOs) located in the skeletal muscles provide the central nervous system with information about muscle tension. The ensemble firing of all GTO receptors in the muscle has been hypothesized to represent a reliable measure of the whole muscle force but the precision and accuracy of that information are largely unknown because it is impossible to record activity simultaneously from all GTOs in a muscle. In this study, we combined a new mathematical model of force sampling and transduction in individual GTOs with various models of motor unit (MU) organization and recruitment simulating various normal, pathological and neural prosthetic conditions. Our study suggests that in the intact muscle the ensemble GTO activity accurately encodes force information according to a nonlinear, monotonic relationship that has its steepest slope for low force levels and tends to saturate at the highest force levels. The relationship between the aggregate GTO activity and whole muscle tension under some pathological conditions is similar to one seen in the intact muscle during rapidly modulated, phasic excitation of the motor pool (typical for many natural movements) but quite different when the muscle is activated slowly or held at a given force level. Substantial deviations were also observed during simulated functional electrical stimulation.

Regulation of traffic and organelle architecture of the ER-Golgi interface by signal transduction.

Science.gov (United States)

Tillmann, Kerstin D; Millarte, Valentina; Farhan, Hesso

2013-09-01

The components that control trafficking between organelles of the secretory pathway as well as their architecture were uncovered to a reasonable extent in the past decades. However, only recently did we begin to explore the regulation of the secretory pathway by cellular signaling. In the current review, we focus on trafficking between the endoplasmic reticulum and the Golgi apparatus. We highlight recent advances that have been made toward a better understanding of how the secretory pathway is regulated by signaling and discuss how this knowledge is important to obtain an integrative view of secretion in the context of other homeostatic processes such as growth and proliferation.

Combined Diffusion Tensor Imaging and Apparent Transverse Relaxation Rate Differentiate Parkinson Disease and Atypical Parkinsonism.

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Du, G; Lewis, M M; Kanekar, S; Sterling, N W; He, L; Kong, L; Li, R; Huang, X

2017-05-01

Both diffusion tensor imaging and the apparent transverse relaxation rate have shown promise in differentiating Parkinson disease from atypical parkinsonism (particularly multiple system atrophy and progressive supranuclear palsy). The objective of the study was to assess the ability of DTI, the apparent transverse relaxation rate, and their combination for differentiating Parkinson disease, multiple system atrophy, progressive supranuclear palsy, and controls. A total of 106 subjects (36 controls, 35 patients with Parkinson disease, 16 with multiple system atrophy, and 19 with progressive supranuclear palsy) were included. DTI and the apparent transverse relaxation rate measures from the striatal, midbrain, limbic, and cerebellar regions were obtained and compared among groups. The discrimination performance of DTI and the apparent transverse relaxation rate among groups was assessed by using Elastic-Net machine learning and receiver operating characteristic curve analysis. Compared with controls, patients with Parkinson disease showed significant apparent transverse relaxation rate differences in the red nucleus. Compared to those with Parkinson disease, patients with both multiple system atrophy and progressive supranuclear palsy showed more widespread changes, extending from the midbrain to striatal and cerebellar structures. The pattern of changes, however, was different between the 2 groups. For instance, patients with multiple system atrophy showed decreased fractional anisotropy and an increased apparent transverse relaxation rate in the subthalamic nucleus, whereas patients with progressive supranuclear palsy showed an increased mean diffusivity in the hippocampus. Combined, DTI and the apparent transverse relaxation rate were significantly better than DTI or the apparent transverse relaxation rate alone in separating controls from those with Parkinson disease/multiple system atrophy/progressive supranuclear palsy; controls from those with Parkinson

The trans-Golgi SNARE syntaxin 10 is required for optimal development of Chlamydia trachomatis

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Andrea L Lucas

2015-09-01

Full Text Available Chlamydia trachomatis, an obligate intracellular pathogen, grows inside of a vacuole, termed the inclusion. Within the inclusion, the organisms differentiate from the infectious elementary body (EB into the reticulate body (RB. The RB communicates with the host cell through the inclusion membrane to obtain the nutrients necessary to divide, thus expanding the chlamydial population. At late time points within the developmental cycle, the RBs respond to unknown molecular signals to redifferentiate into infectious EBs to perpetuate the infection cycle. One strategy for Chlamydia to obtain necessary nutrients and metabolites from the host is to intercept host vesicular trafficking pathways. In this study we demonstrate that a trans-Golgi soluble N-ethylmaleimide–sensitive factor attachment protein (SNARE, syntaxin 10, and/or syntaxin10-associated Golgi elements colocalize with the chlamydial inclusion. We hypothesized that Chlamydia utilizes the molecular machinery of syntaxin 10 at the inclusion membrane to intercept specific vesicular trafficking pathways in order to create and maintain an optimal intra-inclusion environment. To test this hypothesis, we used siRNA knockdown of syntaxin 10 to examine the impact of the loss of syntaxin 10 on chlamydial growth and development. Our results demonstrate that loss of syntaxin 10 leads to defects in normal chlamydial maturation including: variable inclusion size with fewer chlamydial organisms per inclusion, fewer infectious progeny, and delayed or halted RB-EB differentiation. These defects in chlamydial development correlate with an overabundance of NBD-lipid retained by inclusions cultured in syntaxin 10 knockdown cells. Overall, loss of syntaxin 10 at the inclusion membrane negatively affects Chlamydia. Understanding host machinery involved in maintaining an optimal inclusion environment to support chlamydial growth and development is critical towards understanding the molecular signals involved in

Hepatitis C virus replication and Golgi function in brefeldin a-resistant hepatoma-derived cells.

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Rayan Farhat

Full Text Available Recent reports indicate that the replication of hepatitis C virus (HCV depends on the GBF1-Arf1-COP-I pathway. We generated Huh-7-derived cell lines resistant to brefeldin A (BFA, which is an inhibitor of this pathway. The resistant cell lines could be sorted into two phenotypes regarding BFA-induced toxicity, inhibition of albumin secretion, and inhibition of HCV infection. Two cell lines were more than 100 times more resistant to BFA than the parental Huh-7 cells in these 3 assays. This resistant phenotype was correlated with the presence of a point mutation in the Sec7 domain of GBF1, which is known to impair the binding of BFA. Surprisingly, the morphology of the cis-Golgi of these cells remained sensitive to BFA at concentrations of the drug that allowed albumin secretion, indicating a dichotomy between the phenotypes of secretion and Golgi morphology. Cells of the second group were about 10 times more resistant than parental Huh-7 cells to the BFA-induced toxicity. The EC50 for albumin secretion was only 1.5-1.8 fold higher in these cells than in Huh-7 cells. However their level of secretion in the presence of inhibitory doses of BFA was 5 to 15 times higher. Despite this partially effective secretory pathway in the presence of BFA, the HCV infection was almost as sensitive to BFA as in Huh-7 cells. This suggests that the function of GBF1 in HCV replication does not simply reflect its role of regulator of the secretory pathway of the host cell. Thus, our results confirm the involvement of GBF1 in HCV replication, and suggest that GBF1 might fulfill another function, in addition to the regulation of the secretory pathway, during HCV replication.

Effects of Robot Assisted Gait Training in Progressive Supranuclear Palsy (PSP: a preliminary report.

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Patrizio eSale

2014-04-01

Full Text Available Background and Purpose: Progressive supranuclear palsy (PSP is a rare neurodegenerative disease clinically characterized by prominent axial extrapyramidal motor symptoms with frequent falls. Over the last years the introduction of robotic technologies to recover lower limb function has been greatly employed in the rehabilitative practice. This observational trial is aimed at investigating the feasibility, the effectiveness and the efficacy of end-effector robot training in people with PSP.Method: Pilot observational trial.Participants: Five cognitively intact participants with PSP and gait disorders.Interventions: Patients were submitted to a rehabilitative program of robot-assisted walking sessions for 45 minutes, 5 times a week for 4 weeks.Main outcome measures: The spatiotemporal parameters at the beginning (T0 and at the end of treatment (T1 were recorded by a gait analysis laboratory.Results: Robot training was feasible, acceptable and safe and all participants completed the prescribed training sessions. All patients showed an improvement in the gait index (Mean velocity, Cadence, Step length and Step width (T0 versus T1.Conclusions: Robot training is a feasible and safe form of rehabilitation for cognitively intact people with PSP. This innovative approach can contribute to improve lower limb motor recovery. The focus on gait recovery is another quality that makes this research important for clinical practice. On the whole, the simplicity of treatment, the lack of side effects and the positive results in the patients support the recommendation to extend the trials of this treatment. Further investigation regarding the effectiveness of robot training in time is necessary.Trial registration: ClinicalTrials.gov NCT01668407.

The role of the active site Zn in the catalytic mechanism of the GH38 Golgi alpha-mannosidase II: Implications from noeuromycin inhibition

DEFF Research Database (Denmark)

Bols, Mikael; Kuntz, Douglas A.; Rose, David R.

2006-01-01

Golgi alpha-mannosidase II (GMII) is a Family 38 glycosyl hydrolase involved in the eukaryotic N-glycosylation pathway in protein synthesis. Understanding of its catalytic mechanism has been of interest for the development of specific inhibitors that could lead to novel anti-metastatic or anti-in...

Research advances in association between Golgi protein 73 and liver diseases

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WEI Fengxian

2017-08-01

Full Text Available Golgi protein 73 (GP73 has a very low expression level in normal people, while it has a significantly higher expression level in patients with liver diseases and hepatocellular carcinoma (HCC, and therefore, it may become a new marker for HCC. This article introduces the distribution of GP73 in human body and definitions of different subtypes of GP73 and elaborates on its association with benign/malignant liver diseases and surgical operation based on the subtypes of GP73, as well as the application of GP73 in the differentiation of benign/malignant liver diseases. Since GP73 is closely associated with the development, progression, and prognosis of liver diseases, this article summarizes the latest advances in basic research, introduces the structural basis of fucosylated GP73 and proliferation, migration, and invasion of hepatoma cells and known signaling pathways, and lists the factors which affect the expression of GP73.

GOLGA2, Encoding A Master Regulator of Golgi Apparatus, Is Mutated in A Patient with A Neuromuscular Disorder

OpenAIRE

Shamseldin, Hanan E; Bennett, Alexis H; Alfadhel, Majid; Gupta, Vandana; Alkuraya, Fowzan S

2016-01-01

Golgi apparatus (GA) is a membrane-bound organelle that serves a multitude of critical cellular functions including protein secretion and sorting, and cellular polarity. Many Mendelian diseases are caused by mutations in genes encoding various components of GA. GOLGA2 encodes GM130, a necessary component for the assembly of GA as a single complex, and its deficiency has been found to result in severe cellular phenotypes. We describe the first human patient with a homozygous apparently loss of...

Cortical thickness, surface area and volume measures in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy.

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Amanda Worker

Full Text Available Parkinson's disease (PD, Multiple System Atrophy (MSA and Progressive Supranuclear Palsy (PSP are neurodegenerative diseases that can be difficult to distinguish clinically. The objective of the current study was to use surface-based analysis techniques to assess cortical thickness, surface area and grey matter volume to identify unique morphological patterns of cortical atrophy in PD, MSA and PSP and to relate these patterns of change to disease duration and clinical features.High resolution 3D T1-weighted MRI volumes were acquired from 14 PD patients, 18 MSA, 14 PSP and 19 healthy control participants. Cortical thickness, surface area and volume analyses were carried out using the automated surface-based analysis package FreeSurfer (version 5.1.0. Measures of disease severity and duration were assessed for correlation with cortical morphometric changes in each clinical group.Results show that in PSP, widespread cortical thinning and volume loss occurs within the frontal lobe, particularly the superior frontal gyrus. In addition, PSP patients also displayed increased surface area in the pericalcarine. In comparison, PD and MSA did not display significant changes in cortical morphology.These results demonstrate that patients with clinically established PSP exhibit distinct patterns of cortical atrophy, particularly affecting the frontal lobe. These results could be used in the future to develop a useful clinical application of MRI to distinguish PSP patients from PD and MSA patients.

A follow-up study on brainstem atrophy in progressive supranuclear palsy. When does brain MRI contribute to the differential diagnosis between progressive supranuclear palsy and Parkinson disease?

International Nuclear Information System (INIS)

Yamamoto, Toshiyuki; Oya, Yasushi; Ogawa, Masafumi; Ogata, Katsuhisa; Kawai, Mitsuru

2003-01-01

The objective of this study was to investigate when the MRI can discriminate progressive supranuclear palsy (PSP) from Parkinson disease (PD). We obtained the following parameters using T1-weighted axial images of the midbrain and the middle pons from 40 studies of 17 PSP patients and 26 studies of 26 PD patients; anteroposterior diameter of the pons (Pons AP), anteroposterior length of the pontine tegmentum (Pons T), anteroposterior diameter of the midbrain (Midbrain AP), ratio of anteroposterior diameter of the pontine base to that of the pontine tegmentum (Pons B/T ratio), ratio of the sum of the bilateral crus cerebri widths to the midbrain AP (Midbrain [Cr+Cl]/AP ratio). All the PSP patients were studied more than twice and each study was classified into four groups according to the duration of the illness; less than 24 months (7 studies), from 24 to 47 months (10 studies), from 48 to 71 months (14 studies) and 72 months or longer (9 studies). The first MRI studies (duration of disease 39.9±22.1 months) were compared with the second studies (duration of disease 67.6±31.6 months) in 17 PSP patients. Pons AP, Pons T, and Midbrain AP were significantly smaller in the second studies, indicating progressive pontine and midbrain atrophy. Compared with the PD group, the PSP group showed significant atrophy four years after onset of the disease in Pons AP and two years in Pons T. Pons B/T ratio, and Midbrain [Cr+Cl]/AP ratio were significantly smaller in the PSP group two years after onset, suggesting midbrain and pontine tegmentum atrophy. The diagnostic MRI criteria of Pons B/T ratio more than four and Midbrain [Cr+Cl]/AP ratio more than two each showed accuracy in PSP of more than 70% two years after onset. Discrimination of PSP from PD was difficult during the first two years after onset. The atrophic process in the midbrain and the pontine tegmentum may precede that of the pontine base. Pons B/T ratio and Midbrain [Cr+Cl]/AP ratio presented here are potentially

Influence of copper on the Golgi apparatus of the meristematic cells of the horse-bean - Vicia faba c. v. Povazsky

Energy Technology Data Exchange (ETDEWEB)

Kostal, L

1974-01-01

The influence of copper on the Golgi apparatus of beans was investigated. At 1 mg/l copper was toxic within 24 hours. After application of 1 mg/l Cu, a striking increase in the number of split vesicles was noted together with a significant decrease in the number of cisterns. The endoplasmic reticulum is often fragmented after application of Cu, showing separation of membrane.

Two endoplasmic reticulum (ER) membrane proteins that facilitate ER-to-Golgi transport of glycosylphosphatidylinositol-anchored proteins.

Science.gov (United States)

Barz, W P; Walter, P

1999-04-01

Many eukaryotic cell surface proteins are anchored in the lipid bilayer through glycosylphosphatidylinositol (GPI). GPI anchors are covalently attached in the endoplasmic reticulum (ER). The modified proteins are then transported through the secretory pathway to the cell surface. We have identified two genes in Saccharomyces cerevisiae, LAG1 and a novel gene termed DGT1 (for "delayed GPI-anchored protein transport"), encoding structurally related proteins with multiple membrane-spanning domains. Both proteins are localized to the ER, as demonstrated by immunofluorescence microscopy. Deletion of either gene caused no detectable phenotype, whereas lag1Delta dgt1Delta cells displayed growth defects and a significant delay in ER-to-Golgi transport of GPI-anchored proteins, suggesting that LAG1 and DGT1 encode functionally redundant or overlapping proteins. The rate of GPI anchor attachment was not affected, nor was the transport rate of several non-GPI-anchored proteins. Consistent with a role of Lag1p and Dgt1p in GPI-anchored protein transport, lag1Delta dgt1Delta cells deposit abnormal, multilayered cell walls. Both proteins have significant sequence similarity to TRAM, a mammalian membrane protein thought to be involved in protein translocation across the ER membrane. In vivo translocation studies, however, did not detect any defects in protein translocation in lag1Delta dgt1Delta cells, suggesting that neither yeast gene plays a role in this process. Instead, we propose that Lag1p and Dgt1p facilitate efficient ER-to-Golgi transport of GPI-anchored proteins.

The regulation of ER export and Golgi retention of ST3Gal5 (GM3/GM4 synthase) and B4GalNAcT1 (GM2/GD2/GA2 synthase) by arginine/lysine-based motif adjacent to the transmembrane domain.

Science.gov (United States)

Uemura, Satoshi; Shishido, Fumi; Kashimura, Madoka; Inokuchi, Jin-ichi

2015-12-01

In the Golgi maturation model, the Golgi cisternae dynamically mature along a secretory pathway. In this dynamic process, glycosyltransferases are transported from the endoplasmic reticulum (ER) to the Golgi apparatus where they remain and function. The precise mechanism behind this maturation process remains unclear. We investigated two glycosyltransferases, ST3Gal5 (ST3G5) and B4GalNAcT1 (B4GN1), involved in ganglioside synthesis and examined their signal sequences for ER export and Golgi retention. Reports have suggested that the [R/K](X)[R/K] motif functions as an ER exporting signal; however, this signal sequence is insufficient in stably expressed, full-length ST3G5. Through further analysis, we have clarified that the (2)R(3)R(X)(5) (9)K(X)(3) (13)K sequence in ST3G5 is essential for ER export. We have named the sequence the R/K-based motif. On the other hand, for ER export of B4GN1, the homodimer formation in addition to the R/K-based motif is required for ER export suggesting the importance of unidentified lumenal side interaction. We found that ST3G5 R2A/R3A and K9A/K13A mutants localized not only in Golgi apparatus but also in endosomes. Furthermore, the amounts of mature type asparagine-linked (N)-glycans in ST3G5 R2A/R3A and K9A/K13A mutants were decreased compared with those in wild-type proteins, and the stability of the mutants was lower. These results suggest that the R/K-based motif is necessary for the Golgi retention of ST3G5 and that the retention is involved in the maturation of N-glycans and in stability. Thus, several basic amino acids located on the cytoplasmic tail of ST3G5 play important roles in both ER export and Golgi retention. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Progressive supranuclear palsy: neuronal and glial cytoskeletal pathology in the higher order processing autonomic nuclei of the lower brainstem.

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Rüb, U; Del Tredici, K; Schultz, C; de Vos, R A I; Jansen Steur, E N H; Arai, K; Braak, H

2002-02-01

The medial and lateral parabrachial nuclei (MPB, LPB), the gigantocellular reticular nucleus (GI), the raphes magnus (RMG) and raphes obscurus nuclei (ROB), as well as the intermediate reticular zone (IRZ) represent pivotal subordinate brainstem centres, all of which control autonomic functions. In this study, we investigated the occurrence and severity of the neuronal and glial cytoskeletal pathology in these six brainstem nuclei from 17 individuals with clinically diagnosed and neuropathologically confirmed progressive supranuclear palsy (PSP). The association between the severity of the pathology and the duration of the disease was investigated by means of correlation analysis. The brainstem nuclei in all of the PSP cases were affected by the neuronal cytoskeletal pathology, with the IRZ and GI regularly showing severe involvement, the MPB, RMG, and ROB marked involvement, and the LPB mild involvement. In the six nuclear greys studied, glial cells undergo alterations of their cytoskeleton on an irregular basis, whereby diseased oligodendrocytes predominantly presented as coiled bodies and affected astrocytes as thorn-shaped astrocytes. In all six nuclei, the severity of the neuronal or glial cytoskeletal pathology showed no correlation with the duration of PSP. In view of their functional role, the neuronal pathology in the nuclei studied offers a possible explanation for the autonomic dysfunctions that eventually develop in the course of PSP.

Prostaglandin E (dmPGE{sub 2}) action in vitro on the activity of rat liver Golgi apparatus galactosyltransferase

Energy Technology Data Exchange (ETDEWEB)

Kordowiak, A.M.; Tomecki, J.; Procyk, K.; Kapusta, P. [Uniwersytet Jagiellonski, Cracow (Poland)

1993-12-31

In vitro addition of 16,16`-dimethyl prostaglandin E{sub 2} to Golgi-rich membrane fraction in final concentration of 0.1 {mu}g/1 mg of protein increased generally the activity of galactosyltransferase in comparison with control. The percentage of phospholipids in the whole fraction was similar in both investigated groups, only the sum of phosphatidylenoamine + phosphatidic acid was significantly lower after addition of dmPGE{sub 2} than in the control (0.001 < P < 0.01). (author). 25 refs, 2 figs, 1 tab.

VvGONST-A and VvGONST-B are Golgi-localised GDP-sugar transporters in grapevine (Vitis vinifera L.).

Science.gov (United States)

Utz, Daniella; Handford, Michael

2015-02-01

Plant nucleotide-sugar transporters (NSTs) are responsible for the import of nucleotide-sugar substrates into the Golgi lumen, for subsequent use in glycosylation reactions. NSTs are specific for either GDP- or UDP-sugars, and almost all transporters studied to date have been isolated from Arabidopsis thaliana L. In order to determine the conservation of the import mechanism in other higher plant species, here we report the identification and characterisation of VvGONST-A and VvGONST-B from grapevine (Vitis vinifera L. cv. Thompson Seedless), which are the orthologues of the GDP-sugar transporters GONST3 and GONST4 in Arabidopsis. Both grapevine NSTs possess the molecular features characteristic of GDP-sugar transporters, including a GDP-binding domain (GXL/VNK) towards the C-terminal. VvGONST-A and VvGONST-B expression is highest at berry setting and decreases throughout berry development and ripening. Moreover, we show using green fluorescent protein (GFP) tagged versions and brefeldin A treatments, that both are localised in the Golgi apparatus. Additionally, in vitro transport assays after expression of both NSTs in tobacco leaves indicate that VvGONST-A and VvGONST-B are capable of transporting GDP-mannose and GDP-glucose, respectively, but not a range of other UDP- and GDP-sugars. The possible functions of these NSTs in glucomannan synthesis and/or glycosylation of sphingolipids are discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Progressive supranuclear palsy presenting as primary lateral sclerosis but lacking parkinsonism, gaze palsy, aphasia, or dementia.

Science.gov (United States)

Nagao, Shigeto; Yokota, Osamu; Nanba, Reiko; Takata, Hiroshi; Haraguchi, Takashi; Ishizu, Hideki; Ikeda, Chikako; Takeda, Naoya; Oshima, Etsuko; Sakane, Katsuaki; Terada, Seishi; Ihara, Yuetsu; Uchitomi, Yosuke

2012-12-15

We report an autopsy case of progressive supranuclear palsy (PSP) that clinically showed only slowly progressive and symmetric upper motor neuron syndrome over a disease course of 12 years. A female patient initially exhibited dysarthria at the age of 65, followed by gait disturbance and dysphagia. Neurological examination at age 67 disclosed pseudobulbar palsy, spastic gait, hyperreflexia, and presence of bilateral Hoffmann and Babinski signs. However, muscle atrophy, weakness, evidence of denervation on electromyography, vertical gaze palsy, parkinsonism, gait freezing, aphasia, speech apraxia, or dementia was not noted throughout the course. She was clinically diagnosed as having motor neuron disease consistent with so-called primary lateral sclerosis. Pathological examination disclosed histopathological features of PSP, including argyrophilic and tau-positive tufted astrocytes, neurofibrillary tangles, coiled bodies, and thread-like processes in the motor cortex and superior frontal gyrus, and to a lesser degree, in the basal ganglia and brain stem nuclei. In addition, severe fibrillary gliosis was noted in the precentral gyrus and corticospinal tract, being consistent with upper motor neuron syndrome observed in this case. No TAR-DNA binding protein 43-positive lesion, FUS pathology, Bunina body, or Lewy body-like hyaline inclusion was noted in the motor cortex or lower motor neurons. These findings suggest that when tau pathology is prominent in the motor cortex but is minimal in the basal ganglia and brain stem nuclei, a PSP case can lack all classic clinical features of PSP and show only slowly progressive upper motor syndrome, consistent with clinical picture of primary lateral sclerosis. Copyright © 2012 Elsevier B.V. All rights reserved.

Cholesterol Regulates Syntaxin 6 Trafficking at trans-Golgi Network Endosomal Boundaries

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Meritxell Reverter

2014-05-01

Full Text Available Inhibition of cholesterol export from late endosomes causes cellular cholesterol imbalance, including cholesterol depletion in the trans-Golgi network (TGN. Here, using Chinese hamster ovary (CHO Niemann-Pick type C1 (NPC1 mutant cell lines and human NPC1 mutant fibroblasts, we show that altered cholesterol levels at the TGN/endosome boundaries trigger Syntaxin 6 (Stx6 accumulation into VAMP3, transferrin, and Rab11-positive recycling endosomes (REs. This increases Stx6/VAMP3 interaction and interferes with the recycling of αVβ3 and α5β1 integrins and cell migration, possibly in a Stx6-dependent manner. In NPC1 mutant cells, restoration of cholesterol levels in the TGN, but not inhibition of VAMP3, restores the steady-state localization of Stx6 in the TGN. Furthermore, elevation of RE cholesterol is associated with increased amounts of Stx6 in RE. Hence, the fine-tuning of cholesterol levels at the TGN-RE boundaries together with a subset of cholesterol-sensitive SNARE proteins may play a regulatory role in cell migration and invasion.

MRI comparative study of the progressive supranuclear palsy, striatonigral degeneration and Parkinson disease

International Nuclear Information System (INIS)

Wu Wulin; Lou Mingwu; Wang Xiaoyi; Liao Weihua

2009-01-01

Objective: To provide a reliable differential diagnosis among the progressive supranuclear palsy (PSP), striatonigral degeneration (SND) and Parkinson disease (PD). Methods: Conventional MRI data in clinically proved PSP (8 cases), SND (9 cases), PD (12 cases) and 12 normal controls were retrospectively analyzed. Midbrain area, pons area, pons diameter and middle cerebellar peduncles width were measured. The ratio of pons area over midbrain area (pons area / midbrain area) was calculated in all patients and normal controls. Then one way ANOVA and a Kruskal-Wallis H test were used for statistical analysis. Results: Midbrain area of the PSP group [(85.8 ± 12.0 mm 2 ] was the smallest, and there was statistically significant difference (P 2 ], PD group [(133.5 ± 10.8)mm 2 ] and the control group [(135.9 ± 7.5) mm 2 ]. There was no overlapping in the distribution of midbrain area between the PSP group (66.0-98.2 mm 2 ) and SND, PD and normal groups (116.2-142.1, 110.8-146.2 and 121.7-145.8 mm 2 ). The pons area-midbrain area ratio (P/M) of the PSP group (5.9 ± 0.8) was the largest in four groups, and there was statistically significant difference (P 2 , (18.6 ± 2.0) mm and (12.9 ± 2.4) mm] in all groups, and significant difference (P 2 , (22.7 ± 1.7) mm and (16.3 ± 1.1) mm], PD group [3.8 ± 0.3, (500.2 ± 25.8) mm 2 , (23.7 ± 1.0) mm and (16.8 ± 1.1) mm] and the control group [3.8 ± 0.3, (508.8 ± 20.6) mm 2 , (23.2 ± 1.2) mm and (16.4 ± 0.9) mm]. But the PD group and control group had no statistically significant difference in the midbrain area, pons area, pons diameter, P/M and middle cerebellar peduncles width (P > 0.05). Conclusion: MRI measurements helps in the differential diagnosis among PSP, SND and PD. (authors)

The Golgi-Localized γ-Ear-Containing ARF-Binding (GGA Proteins Alter Amyloid-β Precursor Protein (APP Processing through Interaction of Their GAE Domain with the Beta-Site APP Cleaving Enzyme 1 (BACE1.

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Bjoern von Einem

Full Text Available Proteolytic processing of amyloid-β precursor protein (APP by beta-site APP cleaving enzyme 1 (BACE1 is the initial step in the production of amyloid beta (Aβ, which accumulates in senile plaques in Alzheimer's disease (AD. Essential for this cleavage is the transport and sorting of both proteins through endosomal/Golgi compartments. Golgi-localized γ-ear-containing ARF-binding (GGA proteins have striking cargo-sorting functions in these pathways. Recently, GGA1 and GGA3 were shown to interact with BACE1, to be expressed in neurons, and to be decreased in AD brain, whereas little is known about GGA2. Since GGA1 impacts Aβ generation by confining APP to the Golgi and perinuclear compartments, we tested whether all GGAs modulate BACE1 and APP transport and processing. We observed decreased levels of secreted APP alpha (sAPPα, sAPPβ, and Aβ upon GGA overexpression, which could be reverted by knockdown. GGA-BACE1 co-immunoprecipitation was impaired upon GGA-GAE but not VHS domain deletion. Autoinhibition of the GGA1-VHS domain was irrelevant for BACE1 interaction. Our data suggest that all three GGAs affect APP processing via the GGA-GAE domain.

[Submicroscopic changes in ciliated cells of the epithelium of the oviduct in cows during the estrus cycle].

Science.gov (United States)

Uhrín, V; Kliment, J

1983-03-01

The submicroscopic changes in the ciliary cells of the ampullar part of oviduct are of qualitative as well as quantitative nature. The mitochondria are mainly located in the supranuclear region. They are small, having densely arranged lamelliform cristae and dense matrix. They have the largest volume in metoestrus and the highest number and the largest surface already during oestrus. The volume and surface of granular endoplasmic reticulum culminates already during pro-oestrus. The reticulum occurs mainly over the nucleus where it produces tubuli densely covered with ribosomes which begin to dilate already during pro-oestrus. The Golgi apparatus and the membranes of smooth reticulum are poorly developed and their quantitative changes during the cycle are not significant. Various forms of lysosomes, whose volume reaches its maximum in dioestrus and during pro-oestrus, constitute a constant component of cytoplasm. Secretory granules occur only rarely in these cells. Kinocilia grow from the basal corpuscles and are more frequent on cells with a light cytoplasm. Higher-density cells have more micro-villi between kinocilia. Deciliation with the disintegration of membrane, filaments and often also the basal corpuscles is observed during metoestrus and at the beginning of dioestrus. Reciliation begins with the formation of basal corpuscles and their replication at the end of dioestrus and in pro-oestrus. The frequency of ciliary regeneration is comparatively small.

Disturbed neuronal ER-Golgi sorting of unassembled glycine receptors suggests altered subcellular processing is a cause of human hyperekplexia.

Science.gov (United States)

Schaefer, Natascha; Kluck, Christoph J; Price, Kerry L; Meiselbach, Heike; Vornberger, Nadine; Schwarzinger, Stephan; Hartmann, Stephanie; Langlhofer, Georg; Schulz, Solveig; Schlegel, Nadja; Brockmann, Knut; Lynch, Bryan; Becker, Cord-Michael; Lummis, Sarah C R; Villmann, Carmen

2015-01-07

Recent studies on the pathogenic mechanisms of recessive hyperekplexia indicate disturbances in glycine receptor (GlyR) α1 biogenesis. Here, we examine the properties of a range of novel glycine receptor mutants identified in human hyperekplexia patients using expression in transfected cell lines and primary neurons. All of the novel mutants localized in the large extracellular domain of the GlyR α1 have reduced cell surface expression with a high proportion of receptors being retained in the ER, although there is forward trafficking of glycosylated subpopulations into the ER-Golgi intermediate compartment and cis-Golgi compartment. CD spectroscopy revealed that the mutant receptors have proportions of secondary structural elements similar to wild-type receptors. Two mutants in loop B (G160R, T162M) were functional, but none of those in loop D/β2-3 were. One nonfunctional truncated mutant (R316X) could be rescued by coexpression with the lacking C-terminal domain. We conclude that a proportion of GlyR α1 mutants can be transported to the plasma membrane but do not necessarily form functional ion channels. We suggest that loop D/β2-3 is an important determinant for GlyR trafficking and functionality, whereas alterations to loop B alter agonist potencies, indicating that residues here are critical elements in ligand binding. Copyright © 2015 the authors 0270-6474/15/350422-16$15.00/0.

In silico analysis of the fucosylation-associated genome of the human blood fluke Schistosoma mansoni: cloning and characterization of the enzymes involved in GDP-L-fucose synthesis and Golgi import.

Science.gov (United States)

Peterson, Nathan A; Anderson, Tavis K; Wu, Xiao-Jun; Yoshino, Timothy P

2013-07-09

Carbohydrate structures of surface-expressed and secreted/excreted glycoconjugates of the human blood fluke Schistosoma mansoni are key determinants that mediate host-parasite interactions in both snail and mammalian hosts. Fucose is a major constituent of these immunologically important glycans, and recent studies have sought to characterize fucosylation-associated enzymes, including the Golgi-localized fucosyltransferases that catalyze the transfer of L-fucose from a GDP-L-fucose donor to an oligosaccharide acceptor. Importantly, GDP-L-fucose is the only nucleotide-sugar donor used by fucosyltransferases and its availability represents a bottleneck in fucosyl-glycotope expression. A homology-based genome-wide bioinformatics approach was used to identify and molecularly characterize the enzymes that contribute to GDP-L-fucose synthesis and Golgi import in S. mansoni. Putative functions were further investigated through molecular phylogenetic and immunocytochemical analyses. We identified homologs of GDP-D-mannose-4,6-dehydratase (GMD) and GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase-4-reductase (GMER), which constitute a de novo pathway for GDP-L-fucose synthesis, in addition to a GDP-L-fucose transporter (GFT) that putatively imports cytosolic GDP-L-fucose into the Golgi. In silico primary sequence analyses identified characteristic Rossman loop and short-chain dehydrogenase/reductase motifs in GMD and GMER as well as 10 transmembrane domains in GFT. All genes are alternatively spliced, generating variants of unknown function. Observed quantitative differences in steady-state transcript levels between miracidia and primary sporocysts may contribute to differential glycotope expression in early larval development. Additionally, analyses of protein expression suggest the occurrence of cytosolic GMD and GMER in the ciliated epidermal plates and tegument of miracidia and primary sporocysts, respectively, which is consistent with previous localization of highly

Aberrant accumulation of the diabetes autoantigen GAD65 in Golgi membranes in conditions of ER stress and autoimmunity

DEFF Research Database (Denmark)

Phelps, Edward A; Cianciaruso, Chiara; Michael, Iacovos P

2016-01-01

Pancreatic islet beta cells are particularly susceptible to endoplasmic reticulum (ER) stress, which is implicated in beta cell dysfunction and loss during the pathogenesis of type 1 diabetes (T1D). The peripheral membrane protein GAD65 is an autoantigen in human T1D. GAD65 synthesizes GABA......, an important autocrine and paracrine signaling molecule and a survival factor in islets. We show that ER stress in primary beta cells perturbs the palmitoylation cycle controlling GAD65 endomembrane distribution, resulting in aberrant accumulation of the palmitoylated form in trans-Golgi membranes...... release from stressed and/or damaged beta cells, triggering autoimmunity....

La belle indifférence revisited: a case report on progressive supranuclear palsy misdiagnosed as conversion disorder.

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van Meerkerk-Aanen, Petra J; de Vroege, Lars; Khasho, David; Foruz, Aziza; van Asseldonk, J Thies; van der Feltz-Cornelis, Christina M

2017-01-01

Since the advent of computed tomography and magnetic resonance imaging scans, neurological disorders have less often been falsely labeled as conversion disorder (CD). However, misdiagnosis of a neurological disorder as CD still occurs, especially in cases with insidious onset. Misinterpretation of la belle indifférence may contribute to such misdiagnosis. Here, we describe a case of progressive supranuclear palsy/Richardson's syndrome (PSPS) misdiagnosed as a case of CD. A 62-year-old woman consulted two different neurologists in 2012 because of falling spells since 2009 and was diagnosed with CD. She was referred to the Clinical Center of Excellence for Body, Mind, and Health for treatment of CD. After neurological examination, blood tests, and psychiatric examination, in which la belle indifférence and a history of incest were found, CD was confirmed. However, despite treatment for CD, the patient's physical symptoms deteriorated over a year. After repeated physical and psychiatric examinations, neurocognitive assessment, and consultation with a third neurologist because of suspicion of neurological disease, the patient was diagnosed with PSPS. La belle indifférence may be a psychological sign in the context of CD, but it may also be an expression of lack of mimic due to Parkinsonism or of eye movement disorder in the context of neurological illness. A diagnosis of CD should not be considered definitive if no improvement occurs in terms of physical, mental, and cognitive symptoms despite appropriate therapy. In case of deterioration, neurological reexamination and reinterpretation of la belle indifférence should be considered.

Alteraciones de la morfología dendrítica neuronal en la corteza cerebral de ratones infectados con rabia: un estudio con la técnica de Golgi

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Orlando Torres-Fernández

2007-12-01

Conclusiones. Estos resultados son evidencia de que el virus de la rabia sí puede inducir daño neuronal estructural. Además, esta infección aparentemente interfiere con los mecanismos de impregnación argéntica del método de Golgi.

Cytoarchitectonic and quantitative Golgi study of the hedgehog supraoptic nucleus.

Science.gov (United States)

Caminero, A A; Machín, C; Sanchez-Toscano, F

1992-02-01

A cytoarchitectural study was made of the supraoptic nucleus (SON) of the hedgehog with special attention to the quantitative comparison of its main neuronal types. The main purposes were (1) to relate the characteristics of this nucleus in the hedgehog (a primitive mammalian insectivorous brain) with those in the SONs of more evolutionarily advanced species; (2) to identify quantitatively the dendritic fields of the main neuronal types in the hedgehog SON and to study their synaptic connectivity. From a descriptive standpoint, 3 neuronal types were found with respect to the number of dendritic stems arising from the neuronal soma: bipolar neurons (48%), multipolar neurons (45.5%) and monopolar neurons (6.5%). Within the multipolar type 2 subtypes could be distinguished, taking into account the number of dendritic spines: (a) with few spines (93%) and (b) very spiny (7%). These results indicate that the hedgehog SON is similar to that in other species except for the very spiny neurons, the significance of which is discussed. In order to characterise the main types more satisfactorily (bipolar and multipolars with few spines) we undertook a quantitative Golgi study of their dendritic fields. Although the patterns of the dendritic field are similar in both neuronal types, the differences in the location of their connectivity can reflect functional changes and alterations in relation to the synaptic afferences.

Validation of mobile eye tracking as novel and efficient means for differentiating progressive supranuclear palsy from Parkinson’s disease

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Svenja eMarx

2012-12-01

Full Text Available Background: The decreased ability to carry out vertical saccades is a key symptom of Progressive Supranuclear Palsy (PSP. Objective measurement devices can help to reliably detect subtle eye-movement disturbances to improve sensitivity and specificity of the clinical diagnosis. The present study aims at transferring findings from restricted stationary video-oculography to a wearable head-mounted device, which can be readily applied in clinical practice.Methods: We investigated the eye movements in 10 possible or probable PSP patients, 11 Parkinson’s disease (PD patients and 10 age-matched healthy controls (HC using a mobile, gaze-driven video camera setup (EyeSeeCam. Ocular movements were analyzed during a standardized fixation protocol and in an unrestricted real-life scenario while walking along a corridor.Results: The EyeSeeCam detected prominent impairment of both saccade velocity and amplitude in PSP patients, differentiating them from PD and HCs. Differences were particularly evident for saccades in the vertical plane, and stronger for saccades than for other eye movements. Differences were more pronounced during the standardized protocol than in the real-life scenario. Conclusions: Combined analysis of saccade velocity and saccade amplitude during the fixation protocol with the EyeSeeCam provides a simple, rapid (< 20s and reliable tool to differentiate clinically established PSP patients from PD and HCs. As such, our findings prepare the ground for using wearable eye-tracking in patients with uncertain diagnoses.

Restoration of Compact Golgi Morphology in Advanced Prostate Cancer Enhances Susceptibility to Galectin-1-induced Apoptosis by Modifying Mucin O-glycan Synthesis

OpenAIRE

Petrosyan, Armen; Holzapfel, Melissa S.; Muirhead, David E.; Cheng, Pi-Wan

2014-01-01

Prostate cancer progression is associated with up-regulation of sialyl-T antigen produced by β-galactoside α-2,3-sialyltransferase-1 (ST3Gal1) but not with core 2-associated polylactosamine despite expression of core 2 N-acetylglucosaminyltransferase-L (C2GnT-L/GCNT1). This property allows androgen-refractory prostate cancer cells to evade galectin-1 (LGALS1)-induced apoptosis, but the mechanism is not known. We have recently reported that Golgi targeting of glycosyltransferases is mediated b...

Structures of human Golgi-resident glutaminyl cyclase and its complexes with inhibitors reveal a large loop movement upon inhibitor binding.

Science.gov (United States)

Huang, Kai-Fa; Liaw, Su-Sen; Huang, Wei-Lin; Chia, Cho-Yun; Lo, Yan-Chung; Chen, Yi-Ling; Wang, Andrew H-J

2011-04-08

Aberrant pyroglutamate formation at the N terminus of certain peptides and proteins, catalyzed by glutaminyl cyclases (QCs), is linked to some pathological conditions, such as Alzheimer disease. Recently, a glutaminyl cyclase (QC) inhibitor, PBD150, was shown to be able to reduce the deposition of pyroglutamate-modified amyloid-β peptides in brain of transgenic mouse models of Alzheimer disease, leading to a significant improvement of learning and memory in those transgenic animals. Here, we report the 1.05-1.40 Å resolution structures, solved by the sulfur single-wavelength anomalous dispersion phasing method, of the Golgi-luminal catalytic domain of the recently identified Golgi-resident QC (gQC) and its complex with PBD150. We also describe the high-resolution structures of secretory QC (sQC)-PBD150 complex and two other gQC-inhibitor complexes. gQC structure has a scaffold similar to that of sQC but with a relatively wider and negatively charged active site, suggesting a distinct substrate specificity from sQC. Upon binding to PBD150, a large loop movement in gQC allows the inhibitor to be tightly held in its active site primarily by hydrophobic interactions. Further comparisons of the inhibitor-bound structures revealed distinct interactions of the inhibitors with gQC and sQC, which are consistent with the results from our inhibitor assays reported here. Because gQC and sQC may play different biological roles in vivo, the different inhibitor binding modes allow the design of specific inhibitors toward gQC and sQC.

Parametric imaging of the rate constant K[sub i] using 18Fluoro-L-dopa positron emission tomography in progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Cordes, M. (Neurodegenerative Disorders Centre, Univ. Hospital, Univ. of British Columbia, Vancouver, BC (Canada) Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf-Virchow, Berlin (Germany)); Snow, B.J. (Neurodegenerative Disorders Centre, Univ. Hospital, Univ. of British Columbia, Vancouver, BC (Canada)); Morrison, S. (TRIUMF, Univ. of British Columbia, Vancouver, BC (Canada)); Sossi, V. (TRIUMF, Univ. of British Columbia, Vancouver, BC (Canada)); Ruth, T.J. (TRIUMF, Univ. of British Columbia, Vancouver, BC (Canada)); Calne, D.B. (Neurodegenerative Disorders Centre, Univ. Hospital, Univ. of British Columbia, Vancouver, BC (Canada))

1993-01-01

Positron emission tomography (PET) studies using 18F-L-dopa were carried out in 9 patients with supranuclear palsy and 13 controls. For quantification of PET data a rate constant K[sub i] was calculated for the radiotracer using a graphical method. Corrections for nonspecific activity were performed in both arterial plasma and brain tissue. The purpose of this study was to test the hypothesis that parametric images of the rate constant K mapping can be obtained on a pixel-by-pixel basis using an appropriate mathematical algorithm. K[sub i] values from these parametric images and the graphical approach were compared. Both correlated closely, with y=0.013+0.947[sup *]x, r=0.992 and y=-0.052+1.048[sup *]x, r=0.965 in patients and controls, respectively. Contrast measurements were also performed and showed a striking increase in contrast on parametric images. K mapping offers several advantages over the graphical approach, since parametric images are time-independent, i.e. one image represents the quantitative result of the study. In addition, parmetric images of the rate constant are normalized to arterial plasma radioactivity and corrected for tissue metabolites. Thus, parametric images of K[sub i] in different individuals can be compared directly without further processing in order to assess the nigrostriatal integrity. (orig.)

Cytoarchitectonic and quantitative Golgi study of the hedgehog supraoptic nucleus.

Science.gov (United States)

Caminero, A A; Machín, C; Sanchez-Toscano, F

1992-01-01

A cytoarchitectural study was made of the supraoptic nucleus (SON) of the hedgehog with special attention to the quantitative comparison of its main neuronal types. The main purposes were (1) to relate the characteristics of this nucleus in the hedgehog (a primitive mammalian insectivorous brain) with those in the SONs of more evolutionarily advanced species; (2) to identify quantitatively the dendritic fields of the main neuronal types in the hedgehog SON and to study their synaptic connectivity. From a descriptive standpoint, 3 neuronal types were found with respect to the number of dendritic stems arising from the neuronal soma: bipolar neurons (48%), multipolar neurons (45.5%) and monopolar neurons (6.5%). Within the multipolar type 2 subtypes could be distinguished, taking into account the number of dendritic spines: (a) with few spines (93%) and (b) very spiny (7%). These results indicate that the hedgehog SON is similar to that in other species except for the very spiny neurons, the significance of which is discussed. In order to characterise the main types more satisfactorily (bipolar and multipolars with few spines) we undertook a quantitative Golgi study of their dendritic fields. Although the patterns of the dendritic field are similar in both neuronal types, the differences in the location of their connectivity can reflect functional changes and alterations in relation to the synaptic afferences. Images Fig. 2 Fig. 3 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:1452481

Active Dendrites and Differential Distribution of Calcium Channels Enable Functional Compartmentalization of Golgi Cells.

Science.gov (United States)

Rudolph, Stephanie; Hull, Court; Regehr, Wade G

2015-11-25

Interneurons are essential to controlling excitability, timing, and synaptic integration in neuronal networks. Golgi cells (GoCs) serve these roles at the input layer of the cerebellar cortex by releasing GABA to inhibit granule cells (grcs). GoCs are excited by mossy fibers (MFs) and grcs and provide feedforward and feedback inhibition to grcs. Here we investigate two important aspects of GoC physiology: the properties of GoC dendrites and the role of calcium signaling in regulating GoC spontaneous activity. Although GoC dendrites are extensive, previous studies concluded they are devoid of voltage-gated ion channels. Hence, the current view holds that somatic voltage signals decay passively within GoC dendrites, and grc synapses onto distal dendrites are not amplified and are therefore ineffective at firing GoCs because of strong passive attenuation. Using whole-cell recording and calcium imaging in rat slices, we find that dendritic voltage-gated sodium channels allow somatic action potentials to activate voltage-gated calcium channels (VGCCs) along the entire dendritic length, with R-type and T-type VGCCs preferentially located distally. We show that R- and T-type VGCCs located in the dendrites can boost distal synaptic inputs and promote burst firing. Active dendrites are thus critical to the regulation of GoC activity, and consequently, to the processing of input to the cerebellar cortex. In contrast, we find that N-type channels are preferentially located near the soma, and control the frequency and pattern of spontaneous firing through their close association with calcium-activated potassium (KCa) channels. Thus, VGCC types are differentially distributed and serve specialized functions within GoCs. Interneurons are essential to neural processing because they modulate excitability, timing, and synaptic integration within circuits. At the input layer of the cerebellar cortex, a single type of interneuron, the Golgi cell (GoC), carries these functions. The

The pattern of verbal, visuospatial and procedural learning in Richardson variant of progressive supranuclear palsy in comparison to Parkinson's disease.

Science.gov (United States)

Sitek, Emilia J; Wieczorek, Dariusz; Konkel, Agnieszka; Dąbrowska, Magda; Sławek, Jarosław

2017-08-29

Progressive supranuclear palsy (PSP) is regarded either within spectrum of atypical parkinsonian syndromes or frontotemporal lobar degeneration. We compared the verbal, visuospatial and procedural learning profiles in patients with PSP and Parkinson's disease (PD). Furthermore, the relationship between executive factors (initiation and inhibition) and learning outcomes was analyzed. Thirty-three patients with the clinical diagnosis of PSP-Richardson's syndrome (PSP-RS), 39 patients with PD and 29 age -and education -matched controls were administered Mini-Mental State Examination (MMSE), phonemic and semantic fluency tasks, Auditory Verbal Learning Test (AVLT), Visual Learning and Memory Test for Neuropsychological Assessment by Lamberti and Weidlich (Diagnosticum für Cerebralschädigung, DCS), Tower of Toronto (ToT) and two motor sequencing tasks. Patients with PSP-RS and PD were matched in terms of MMSE scores and mood. Performance on DCS was lower in PSP-RS than in PD. AVLT delayed recall was better in PSP-RS than PD. Motor sequencing task did not differentiate between patients. Scores on AVLT correlated positively with phonemic fluency scores in both PSP-RS and PD. ToT rule violation scores were negatively associated with DCS performance in PSP-RS and PD as well as with AVLT performance in PD. Global memory performance is relatively similar in PSP-RS and PD. Executive factors (initiation and inhibition) are closely related to memory performance in PSP-RS and PD. Visuospatial learning impairment in PSP-RS is possibly linked to impulsivity and failure to inhibit automatic responses.

GPR107, a G-protein-coupled receptor essential for intoxication by Pseudomonas aeruginosa exotoxin A, localizes to the Golgi and is cleaved by furin.

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Tafesse, Fikadu G; Guimaraes, Carla P; Maruyama, Takeshi; Carette, Jan E; Lory, Stephen; Brummelkamp, Thijn R; Ploegh, Hidde L

2014-08-29

A number of toxins, including exotoxin A (PE) of Pseudomonas aeruginosa, kill cells by inhibiting protein synthesis. PE kills by ADP-ribosylation of the translation elongation factor 2, but many of the host factors required for entry, membrane translocation, and intracellular transport remain to be elucidated. A genome-wide genetic screen in human KBM7 cells was performed to uncover host factors used by PE, several of which were confirmed by CRISPR/Cas9-gene editing in a different cell type. Several proteins not previously implicated in the PE intoxication pathway were identified, including GPR107, an orphan G-protein-coupled receptor. GPR107 localizes to the trans-Golgi network and is essential for retrograde transport. It is cleaved by the endoprotease furin, and a disulfide bond connects the two cleaved fragments. Compromising this association affects the function of GPR107. The N-terminal region of GPR107 is critical for its biological function. GPR107 might be one of the long-sought receptors that associates with G-proteins to regulate intracellular vesicular transport. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Voxelwise meta-ananlysis of gray matter anomalies in progressive supranuclear palsy and Parkinson’s disease using anatomic likelihood estimation

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Huifang eShang

2014-02-01

Full Text Available Numerous voxel-based morphometry (VBM studies on gray matter (GM of patients with progressive supranuclear palsy (PSP and Parkinson’s disease (PD have been conducted separately. Identifying the different neuroanatomical changes in GM resulting from PSP and PD through meta-analysis will aid the differential diagnosis of PSP and PD. In this study, a systematic review of VBM studies of patients with PSP and PD relative to healthy controls (HC in the Embase and PubMed databases from January 1995 to April 2013 was conducted. The anatomical distribution of the coordinates of GM differences was meta-analyzed using anatomical likelihood estimation. Separate maps of GM changes were constructed and subtraction meta-analysis was performed to explore the differences in GM abnormalities between PSP and PD. Nine PSP studies and 24 PD studies were included. GM reductions were present in the bilateral thalamus, basal ganglia, midbrain, insular cortex and inferior frontal gyrus, and left precentral gyrus and anterior cingulate gyrus in PSP. Atrophy of GM was concentrated in the bilateral middle and inferior frontal gyrus, precuneus, left precentral gyrus, middle temporal gyrus, right superior parietal lobule, and right cuneus in PD. Subtraction meta-analysis indicated that GM volume was lesser in the bilateral midbrain, thalamus, and insula in PSP compared with that in PD. Our meta-analysis indicated that PSP and PD shared a similar distribution of neuroanatomical changes in the frontal lobe, including inferior frontal gyrus and precentral gyrus, and that atrophy of the midbrain, thalamus, and insula are neuroanatomical markers for differentiating PSP from PD.

Cleavage of ST6Gal I by Radiation-Induced BACE1 Inhibits Golgi-Anchored ST6Gal I-Mediated Sialylation of Integrin β1 and Migration in Colon Cancer Cells

International Nuclear Information System (INIS)

Lee, Minyoung; Park, Jung-Jin; Ko, Young-Gyu; Lee, Yun-Sil

2012-01-01

Previously, we found that β-galactoside α2,6-sialyltransferase (ST6Gal I), an enzyme that adds sialic acids to N-linked oligosaccharides of glycoproteins and is frequently overexpressed in cancer cells, is up-regulated by ionizing radiation (IR) and cleaved to a form possessing catalytic activity comparable to that of the Golgi-localized enzyme. Moreover, this soluble form is secreted into the culture media. Induction of ST6Gal I significantly increased the migration of colon cancer cells via sialylation of integrin β1. Here, we further investigated the mechanisms underlying ST6Gal I cleavage, solubilization and release from cells, and addressed its functions, focusing primarily on cancer cell migration. We performed immunoblotting and lectin affinity assay to analyze the expression of ST6 Gal I and level of sialylated integrin β1. After ionizing radiation, migration of cells was measured by in vitro migration assay. α2, 6 sialylation level of cell surface was analyzed by flow cytometry. Cell culture media were concentrated and then analyzed for soluble ST6Gal I levels using an α2, 6 sialyltransferase sandwich ELISA. We found that ST6Gal I was cleaved by BACE1 (β-site amyloid precursor protein-cleaving enzyme), which was specifically overexpressed in response to IR. The soluble form of ST6Gal I, which also has sialyltransferase enzymatic activity, was cleaved from the Golgi membrane and then released into the culture media. Both non-cleaved and cleaved forms of ST6Gal I significantly increased colon cancer cell migration in a sialylation-dependent manner. The pro-migratory effect of the non-cleaved form of ST6Gal I was dependent on integrin β1 sialylation, whereas that of the cleaved form of ST6Gal I was not, suggesting that other intracellular sialylated molecules apart from cell surface molecules such as integrin β1 might be involved in mediating the pro-migratory effects of the soluble form of ST6Gal I. Moreover, production of soluble form ST6Gal I by

Combined measurement of plasma cystatin C and low-density lipoprotein cholesterol: A valuable tool for evaluating progressive supranuclear palsy.

Science.gov (United States)

Weng, Ruihui; Wei, Xiaobo; Yu, Bin; Zhu, Shuzhen; Yang, Xiaohua; Xie, Fen; Zhang, Mahui; Jiang, Ying; Feng, Zhong-Ping; Sun, Hong-Shuo; Xia, Ying; Jin, Kunlin; Chan, Piu; Wang, Qing; Gao, Xiaoya

2018-07-01

Progressive supranuclear palsy (PSP) was previously thought as a cause of atypical Parkinsonism. Although Cystatin C (Cys C) and low-density cholesterol lipoprotein-C (LDL-C) are known to play critical roles in Parkinsonism, it is unknown whether they can be used as markers to distinguish PSP patients from healthy subjects and to determine disease severity. We conducted a cross-sectional study to determine plasma Cys C/HDL/LDL-C levels of 40 patients with PSP and 40 healthy age-matched controls. An extended battery of motor and neuropsychological tests, including the PSP-Rating Scale (PSPRS), the Non-Motor Symptoms Scale (NMSS), Geriatric Depression Scale (GDS) and Mini-Mental State Examination (MMSE), was used to evaluate the disease severity. Receiver operating characteristic (ROC) curves were adopted to assess the prognostic accuracy of Cys C/LDL-C levels in distinguishing PSP from healthy subjects. Patients with PSP exhibited significantly higher plasma levels of Cys C and lower LDL-C. The levels of plasma Cys C were positively and inversely correlated with the PSPRS/NMSS and MMSE scores, respectively. The LDL-C/HDL-C ratio was positively associated with PSPRS/NMSS and GDS scores. The ROC curve for the combination of Cys C and LDL-C yielded a better accuracy for distinguishing PSP from healthy subjects than the separate curves for each parameter. Plasma Cys C and LDL-C may be valuable screening tools for differentiating PSP from healthy subjects; while they could be useful for the PSP intensifies and severity evaluation. A better understanding of Cys C and LDL-C may yield insights into the pathogenesis of PSP. Copyright © 2018 Elsevier Ltd. All rights reserved.

GOLGA2, encoding a master regulator of golgi apparatus, is mutated in a patient with a neuromuscular disorder.

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Shamseldin, Hanan E; Bennett, Alexis H; Alfadhel, Majid; Gupta, Vandana; Alkuraya, Fowzan S

2016-02-01

Golgi apparatus (GA) is a membrane-bound organelle that serves a multitude of critical cellular functions including protein secretion and sorting, and cellular polarity. Many Mendelian diseases are caused by mutations in genes encoding various components of GA. GOLGA2 encodes GM130, a necessary component for the assembly of GA as a single complex, and its deficiency has been found to result in severe cellular phenotypes. We describe the first human patient with a homozygous apparently loss of function mutation in GOLGA2. The phenotype is a neuromuscular disorder characterized by developmental delay, seizures, progressive microcephaly, and muscular dystrophy. Knockdown of golga2 in zebrafish resulted in severe skeletal muscle disorganization and microcephaly recapitulating loss of function human phenotype. Our data suggest an important developmental role of GM130 in humans and zebrafish.

3D Structure and Interaction of p24β and p24δ Golgi Dynamics Domains: Implication for p24 Complex Formation and Cargo Transport.

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Nagae, Masamichi; Hirata, Tetsuya; Morita-Matsumoto, Kana; Theiler, Romina; Fujita, Morihisa; Kinoshita, Taroh; Yamaguchi, Yoshiki

2016-10-09

The p24 family consists of four subfamilies (p24α, p24β, p24γ, and p24δ), and the proteins are thought to form hetero-oligomeric complexes for efficient transport of cargo proteins from the endoplasmic reticulum to the Golgi apparatus. The proteins possess a conserved luminal Golgi dynamics (GOLD) domain, whose functions are largely unknown. Here, we present structural and biochemical studies of p24β1 and p24δ1 GOLD domains. Use of GOLD domain-deleted mutants revealed that the GOLD domain of p24δ1 is required for proper p24 hetero-oligomeric complex formation and efficient transport of GPI-anchored proteins. The p24β1 and p24δ1 GOLD domains share a common β-sandwich fold with a characteristic intrasheet disulfide bond. The GOLD domain of p24δ1 crystallized as dimers, allowing the analysis of a homophilic interaction site. Surface plasmon resonance and solution NMR analyses revealed that p24β1 and p24δ1 GOLD domains interact weakly (K d = ~10 -4 M). Bi-protein titration provided interaction site maps. We propose that the heterophilic interaction of p24 GOLD domains contributes to the formation of the p24 hetero-oligomeric complex and to efficient cargo transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of magnetic resonance planimetry and magnetic resonance parkinsonism index in discriminating Parkinson’s disease and progressive supranuclear palsy: a retrospective study based on 1.5 and 3 T MRI

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Nizamani WM

2017-10-01

Full Text Available Waseem Mehmood Nizamani,1 Fatima Mubarak,1 Muhammad Danish Barakzai,1 Muhammad Saad Ahmed2 1Department of Radiology, Aga Khan University Hospital, Karachi, Pakistan, 2Department of Radiology, Ziauddin University Hospital, Karachi, Pakistan Objective: The objective of the study was to assess magnetic resonance (MR planimetric measurements and MR parkinsonism index (MRPI in differentiating progressive supranuclear palsy (PSP from Parkinson’s disease (PD using 1.5 and 3 T MRI scanner. Subjects and methods: After ethical approval was obtained, analysis of 34 consecutive patients with PSP, 34 patients with PD and 34 healthy controls (HCs was performed. HCs were age-matched adults without any history of neurodegenerative disease or movement disorders. Retrospective data from the past 10 years (from January 2006 to December 2015 were obtained from the Hospital Information Management System, and informed consent was obtained from all participants. The measurements of pons area–midbrain area ratio (P/M and MCP width–superior cerebellar peduncle (SCP width ratio (MCP/SCP were used, and MRPI was calculated by the formula ([P/M]×[MCP/SCP]. Results: Midbrain area and SCP width in patients with PSP (19 males, 15 females; mean age =66.7 years were significantly (P<0.001 smaller than in patients with PD (20 males, 14 females; mean age =66.7 years and control participants (17 males, 17 females; mean age =66.1 years. P/M and MCP/SCP were significantly higher in patients with PSP than in patients with PD and control participants. All measurements showed some overlap of values between patients with PSP and patients from PD group and control participants. MRPI value was significantly higher in patients with PSP (mean 21.00 than in patients with PD (mean 9.50; P<0.001 and control participants (mean 9.6; P<0.001, without any overlap of values among groups. No correlation was found between the duration of disease, PSP rating scale, PSP staging system and MRPI in

Golgi Study of Medium Spiny Neurons from Dorsolateral Striatum of the Turtle Trachemys scripta elegans.

Science.gov (United States)

González, Carolina; Mendoza, Janeth; Avila-Costa, María Rosa; Arias, Juan M; Barral, Jaime

2013-10-25

Comparative anatomy has shown similarities between reptilian and mammalian basal ganglia. Here the morphological characteristics of the medium spiny neurons (MSN) in the dorsolateral striatum (DLS) of the turtle are described after staining them with the Golgi technique. The soma of MSN in DLS showed three main forms: spherical, ovoid, and fusiform. The number of primary dendritic branches (3-4 dendrites/cell) was less than observed in mammals. The MSN axon originates mainly from the soma, and randomly it emerges at the beginning of the primary dendrite. The main differences between turtle and mammalian MSN were detected on dendritic spines. Short, thin, bifurcated and fungiform types of dendritic spines were observed in the turtle's MSN, according to their shape. In most of the analyzed spines, it was found that its length considerably exceeded that reported in mammals, with dendritic spines up to 8μm in length. These differences could play an important role in the modulation of motor networks preserved along the vertebrate evolution. Copyright © 2013. Published by Elsevier Ireland Ltd.

The Drosophila Neurally Altered Carbohydrate Mutant Has a Defective Golgi GDP-fucose Transporter*

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Geisler, Christoph; Kotu, Varshika; Sharrow, Mary; Rendić, Dubravko; Pöltl, Gerald; Tiemeyer, Michael; Wilson, Iain B. H.; Jarvis, Donald L.

2012-01-01

Studying genetic disorders in model organisms can provide insights into heritable human diseases. The Drosophila neurally altered carbohydrate (nac) mutant is deficient for neural expression of the HRP epitope, which consists of N-glycans with core α1,3-linked fucose residues. Here, we show that a conserved serine residue in the Golgi GDP-fucose transporter (GFR) is substituted by leucine in nac1 flies, which abolishes GDP-fucose transport in vivo and in vitro. This loss of function is due to a biochemical defect, not to destabilization or mistargeting of the mutant GFR protein. Mass spectrometry and HPLC analysis showed that nac1 mutants lack not only core α1,3-linked, but also core α1,6-linked fucose residues on their N-glycans. Thus, the nac1 Gfr mutation produces a previously unrecognized general defect in N-glycan core fucosylation. Transgenic expression of a wild-type Gfr gene restored the HRP epitope in neural tissues, directly demonstrating that the Gfr mutation is solely responsible for the neural HRP epitope deficiency in the nac1 mutant. These results validate the Drosophila nac1 mutant as a model for the human congenital disorder of glycosylation, CDG-IIc (also known as LAD-II), which is also the result of a GFR deficiency. PMID:22745127

Golgi Outpost Synthesis Impaired by Toxic Polyglutamine Proteins Contributes to Dendritic Pathology in Neurons

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Chang Geon Chung

2017-07-01

Full Text Available Dendrite aberration is a common feature of neurodegenerative diseases caused by protein toxicity, but the underlying mechanisms remain largely elusive. Here, we show that nuclear polyglutamine (polyQ toxicity resulted in defective terminal dendrite elongation accompanied by a loss of Golgi outposts (GOPs and a decreased supply of plasma membrane (PM in Drosophila class IV dendritic arborization (da (C4 da neurons. mRNA sequencing revealed that genes downregulated by polyQ proteins included many secretory pathway-related genes, including COPII genes regulating GOP synthesis. Transcription factor enrichment analysis identified CREB3L1/CrebA, which regulates COPII gene expression. CrebA overexpression in C4 da neurons restores the dysregulation of COPII genes, GOP synthesis, and PM supply. Chromatin immunoprecipitation (ChIP-PCR revealed that CrebA expression is regulated by CREB-binding protein (CBP, which is sequestered by polyQ proteins. Furthermore, co-overexpression of CrebA and Rac1 synergistically restores the polyQ-induced dendrite pathology. Collectively, our results suggest that GOPs impaired by polyQ proteins contribute to dendrite pathology through the CBP-CrebA-COPII pathway.

Distributions of 35S-sulfate and 3H-glucosamine in the angular region of the hamster: light and electron microscopic autoradiography

International Nuclear Information System (INIS)

Ohnishi, Y.; Taniguchi, Y.

1983-01-01

The distribution of 35 S-sulfate and 3 H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of 35 S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of 3 H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid

Kidney-differentiated cells derived from Lowe Syndrome patient's iPSCs show ciliogenesis defects and Six2 retention at the Golgi complex.

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Wen-Chieh Hsieh

Full Text Available Lowe syndrome is an X-linked condition characterized by congenital cataracts, neurological abnormalities and kidney malfunction. This lethal disease is caused by mutations in the OCRL1 gene, which encodes for the phosphatidylinositol 5-phosphatase Ocrl1. While in the past decade we witnessed substantial progress in the identification and characterization of LS patient cellular phenotypes, many of these studies have been performed in knocked-down cell lines or patient's cells from accessible cell types such as skin fibroblasts, and not from the organs affected. This is partially due to the limited accessibility of patient cells from eyes, brain and kidneys. Here we report the preparation of induced pluripotent stem cells (iPSCs from patient skin fibroblasts and their reprogramming into kidney cells. These reprogrammed kidney cells displayed primary cilia assembly defects similar to those described previously in cell lines. Additionally, the transcription factor and cap mesenchyme marker Six2 was substantially retained in the Golgi complex and the functional nuclear-localized fraction was reduced. These results were confirmed using different batches of differentiated cells from different iPSC colonies and by the use of the human proximal tubule kidney cell line HK2. Indeed, OCRL1 KO led to both ciliogenesis defects and Six2 retention in the Golgi complex. In agreement with Six2's role in the suppression of ductal kidney lineages, cells from this pedigree were over-represented among patient kidney-reprogrammed cells. We speculate that this diminished efficacy to produce cap mesenchyme cells would cause LS patients to have difficulties in replenishing senescent or damaged cells derived from this lineage, particularly proximal tubule cells, leading to pathological scenarios such as tubular atrophy.

Diffusion tensor imaging of Parkinson's disease, multiple system atrophy and progressive supranuclear palsy: a tract-based spatial statistics study.

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Amanda Worker

Full Text Available Although often clinically indistinguishable in the early stages, Parkinson's disease (PD, Multiple System Atrophy (MSA and Progressive Supranuclear Palsy (PSP have distinct neuropathological changes. The aim of the current study was to identify white matter tract neurodegeneration characteristic of each of the three syndromes. Tract-based spatial statistics (TBSS was used to perform a whole-brain automated analysis of diffusion tensor imaging (DTI data to compare differences in fractional anisotropy (FA and mean diffusivity (MD between the three clinical groups and healthy control subjects. Further analyses were conducted to assess the relationship between these putative indices of white matter microstructure and clinical measures of disease severity and symptoms. In PSP, relative to controls, changes in DTI indices consistent with white matter tract degeneration were identified in the corpus callosum, corona radiata, corticospinal tract, superior longitudinal fasciculus, anterior thalamic radiation, superior cerebellar peduncle, medial lemniscus, retrolenticular and anterior limb of the internal capsule, cerebral peduncle and external capsule bilaterally, as well as the left posterior limb of the internal capsule and the right posterior thalamic radiation. MSA patients also displayed differences in the body of the corpus callosum corticospinal tract, cerebellar peduncle, medial lemniscus, anterior and superior corona radiata, posterior limb of the internal capsule external capsule and cerebral peduncle bilaterally, as well as the left anterior limb of the internal capsule and the left anterior thalamic radiation. No significant white matter abnormalities were observed in the PD group. Across groups, MD correlated positively with disease severity in all major white matter tracts. These results show widespread changes in white matter tracts in both PSP and MSA patients, even at a mid-point in the disease process, which are not found in patients

Tetrahymena gene encodes a protein that is homologous with the liver-specific F-antigen and associated with membranes of the Golgi apparatus and transport vesicles

DEFF Research Database (Denmark)

Hummel, R; Nørgaard, P; Andreasen, P H

1992-01-01

The F-antigen is a prominent liver protein which has been extensively used in studies on natural and induced immunological tolerance. However, its intracellular localization and biological function have remained elusive. It has generally been assumed that the F-antigen is confined phylogenetically...... of the Golgi apparatus and transport vesicles pointing to a role of TF-ag in membrane trafficking. Transcription of the TF-ag gene, as determined by run-on analyses, was only detectable in growing cells, and following transfer to starvation condition pre-existing TF-ag mRNA was rapidly degraded. The abundance...

Asparagus IRX9, IRX10, and IRX14A Are Components of an Active Xylan Backbone Synthase Complex that Forms in the Golgi Apparatus.

Science.gov (United States)

Zeng, Wei; Lampugnani, Edwin R; Picard, Kelsey L; Song, Lili; Wu, Ai-Min; Farion, Isabela M; Zhao, Jia; Ford, Kris; Doblin, Monika S; Bacic, Antony

2016-05-01

Heteroxylans are abundant components of plant cell walls and provide important raw materials for the food, pharmaceutical, and biofuel industries. A number of studies in Arabidopsis (Arabidopsis thaliana) have suggested that the IRREGULAR XYLEM9 (IRX9), IRX10, and IRX14 proteins, as well as their homologs, are involved in xylan synthesis via a Golgi-localized complex termed the xylan synthase complex (XSC). However, both the biochemical and cell biological research lags the genetic and molecular evidence. In this study, we characterized garden asparagus (Asparagus officinalis) stem xylan biosynthesis genes (AoIRX9, AoIRX9L, AoIRX10, AoIRX14A, and AoIRX14B) by heterologous expression in Nicotiana benthamiana We reconstituted and partially purified an active XSC and showed that three proteins, AoIRX9, AoIRX10, and AoIRX14A, are necessary for xylan xylosyltranferase activity in planta. To better understand the XSC structure and its composition, we carried out coimmunoprecipitation and bimolecular fluorescence complementation analysis to show the molecular interactions between these three IRX proteins. Using a site-directed mutagenesis approach, we showed that the DxD motifs of AoIRX10 and AoIRX14A are crucial for the catalytic activity. These data provide, to our knowledge, the first lines of biochemical and cell biological evidence that AoIRX9, AoIRX10, and AoIRX14A are core components of a Golgi-localized XSC, each with distinct roles for effective heteroxylan biosynthesis. © 2016 American Society of Plant Biologists. All Rights Reserved.

Distributions of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster: light and electron microscopic autoradiography

Energy Technology Data Exchange (ETDEWEB)

Ohnishi, Y.; Taniguchi, Y.

1983-06-01

The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.

MAPT expression and splicing is differentially regulated by brain region: relation to genotype and implication for tauopathies

Science.gov (United States)

Trabzuni, Daniah; Wray, Selina; Vandrovcova, Jana; Ramasamy, Adaikalavan; Walker, Robert; Smith, Colin; Luk, Connie; Gibbs, J. Raphael; Dillman, Allissa; Hernandez, Dena G.; Arepalli, Sampath; Singleton, Andrew B.; Cookson, Mark R.; Pittman, Alan M.; de Silva, Rohan; Weale, Michael E.; Hardy, John; Ryten, Mina

2012-01-01

The MAPT (microtubule-associated protein tau) locus is one of the most remarkable in neurogenetics due not only to its involvement in multiple neurodegenerative disorders, including progressive supranuclear palsy, corticobasal degeneration, Parksinson's disease and possibly Alzheimer's disease, but also due its genetic evolution and complex alternative splicing features which are, to some extent, linked and so all the more intriguing. Therefore, obtaining robust information regarding the expression, splicing and genetic regulation of this gene within the human brain is of immense importance. In this study, we used 2011 brain samples originating from 439 individuals to provide the most reliable and coherent information on the regional expression, splicing and regulation of MAPT available to date. We found significant regional variation in mRNA expression and splicing of MAPT within the human brain. Furthermore, at the gene level, the regional distribution of mRNA expression and total tau protein expression levels were largely in agreement, appearing to be highly correlated. Finally and most importantly, we show that while the reported H1/H2 association with gene level expression is likely to be due to a technical artefact, this polymorphism is associated with the expression of exon 3-containing isoforms in human brain. These findings would suggest that contrary to the prevailing view, genetic risk factors for neurodegenerative diseases at the MAPT locus are likely to operate by changing mRNA splicing in different brain regions, as opposed to the overall expression of the MAPT gene. PMID:22723018

4-Repeat Tauopathy Neuroimaging Initiative - Cycle 2

Science.gov (United States)

2018-05-01

Corticobasal Degeneration (CBD); Corticobasal Syndrome (CBS); Cortical-basal Ganglionic Degeneration (CBGD); Progressive Supranuclear Palsy (PSP); Nonfluent Variant Primary Progressive Aphasia (nfvPPA); Oligosymptomatic/Variant Progressive Supranuclear Palsy (o/vPSP)

The Prion-like Domain in the Exomer-Dependent Cargo Pin2 Serves as a trans-Golgi Retention Motif

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Alicja M. Ritz

2014-04-01

Full Text Available Prion and prion-like domains (PLDs are found in many proteins throughout the animal kingdom. We found that the PLD in the S. cerevisiae exomer-dependent cargo protein Pin2 is involved in the regulation of protein transport and localization. The domain serves as a Pin2 retention signal in the trans-Golgi network (TGN. Pin2 is localized in a polarized fashion at the plasma membrane of the bud early in the cell cycle and the bud neck at cytokinesis. This polarized localization is dependent on both exo- and endocytosis. Upon environmental stress, Pin2 is rapidly endocytosed, and the PLD aggregates and causes sequestration of Pin2. The aggregation of Pin2 is reversible upon stress removal and Pin2 is rapidly re-exported to the plasma membrane. Altogether, these data uncover a role for PLDs as protein localization elements.

A traffic signal for heterodimeric amino acid transporters to transfer from the ER to the Golgi.

Science.gov (United States)

Ganapathy, Vadivel

2009-01-15

Heterodimeric amino acid transporters represent a unique class of transport systems that consist of a light chain that serves as the 'transporter proper' and a heavy chain that is necessary for targeting the complex to the plasma membrane. The currently prevailing paradigm assigns no role for the light chains in the cellular processing of these transporters. In this issue of the Biochemical Journal, Sakamoto et al. provide evidence contrary to this paradigm. Their studies with the rBAT -b(0,+)AT (related to b(0,+) amino acid transporter-b(0,+)-type amino acid transporter) heterodimeric amino acid transporter show that the C-terminus of the light chain b(0,+)AT contains a sequence motif that serves as the traffic signal for the transfer of the heterodimeric complex from the endoplasmic reticulum to the Golgi. This is a novel function for the light chain in addition to its already established role as the subunit responsible for the transport activity. These new findings also seem to be applicable to other heterodimeric amino acid transporters as well.

The C-terminal region of A-kinase anchor protein 350 (AKAP350A) enables formation of microtubule-nucleation centers and interacts with pericentriolar proteins.

Science.gov (United States)

Kolobova, Elena; Roland, Joseph T; Lapierre, Lynne A; Williams, Janice A; Mason, Twila A; Goldenring, James R

2017-12-15

Microtubules in animal cells assemble (nucleate) from both the centrosome and the cis-Golgi cisternae. A-kinase anchor protein 350 kDa (AKAP350A, also called AKAP450/CG-NAP/AKAP9) is a large scaffolding protein located at both the centrosome and Golgi apparatus. Previous findings have suggested that AKAP350 is important for microtubule dynamics at both locations, but how this scaffolding protein assembles microtubule nucleation machinery is unclear. Here, we found that overexpression of the C-terminal third of AKAP350A, enhanced GFP-AKAP350A(2691-3907), induces the formation of multiple microtubule-nucleation centers (MTNCs). Nevertheless, these induced MTNCs lacked "true" centriole proteins, such as Cep135. Mapping analysis with AKAP350A truncations demonstrated that AKAP350A contains discrete regions responsible for promoting or inhibiting the formation of multiple MTNCs. Moreover, GFP-AKAP350A(2691-3907) recruited several pericentriolar proteins to MTNCs, including γ-tubulin, pericentrin, Cep68, Cep170, and Cdk5RAP2. Proteomic analysis indicated that Cdk5RAP2 and Cep170 both interact with the microtubule nucleation-promoting region of AKAP350A, whereas Cep68 interacts with the distal C-terminal AKAP350A region. Yeast two-hybrid assays established a direct interaction of Cep170 with AKAP350A. Super-resolution and deconvolution microscopy analyses were performed to define the association of AKAP350A with centrosomes, and these studies disclosed that AKAP350A spans the bridge between centrioles, co-localizing with rootletin and Cep68 in the linker region. siRNA-mediated depletion of AKAP350A caused displacement of both Cep68 and Cep170 from the centrosome. These results suggest that AKAP350A acts as a scaffold for factors involved in microtubule nucleation at the centrosome and coordinates the assembly of protein complexes associating with the intercentriolar bridge.

Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) performance in progressive supranuclear palsy and multiple system atrophy.

Science.gov (United States)

Fiorenzato, Eleonora; Weis, Luca; Falup-Pecurariu, Cristian; Diaconu, Stefania; Siri, Chiara; Reali, Elisa; Pezzoli, Gianni; Bisiacchi, Patrizia; Antonini, Angelo; Biundo, Roberta

2016-12-01

To determine if Montreal Cognitive Assessment (MoCA) is more sensitive than the commonly used Mini-Mental State Examination (MMSE) in detecting cognitive abnormalities in patients with probable progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) compared with Parkinson's disease (PD). In this multicenter observational study, MMSE and MoCA were administered in a random order to 130 patients: 35 MSA, 30 PSP and 65 age, and education and gender matched-PD. We assessed between-group differences for MMSE, MoCA, and their subitems. Receiver-operating characteristic (ROC) curves were calculated. The mean MMSE was higher than the mean MoCA score in each MSA (27.7 ± 2.4 vs. 22.9 ± 3.0, p < 0.0001), PSP (26.0 ± 2.9 vs. 18.2 ± 3.9, p < 0.0001), and PD (27.3 ± 2.0 vs. 22.3 ± 3.5, p < 0.0001). MoCA total score as well as its letter fluency subitem differentiated PSP from MSA and PD with high specificity and moderate sensitivity. More specifically, a cut-off score of 7 F-words or less per minute would support a diagnosis of PSP (PSP vs. PD: 86 % specificity, 70 % sensitivity; PSP vs. MSA: 71 % specificity, 70 % sensitivity). By contrast, MMSE presented an overall ceiling effect for most subitems, except for the pentagon scores, where PSP did less well than MSA or PD patients. These preliminary results suggest that PSP and MSA, similar to PD patients, may present normal MMSE and reduced MoCA performance. Overall, MoCA is more sensitive than MMSE in detecting cognitive impairment in atypical parkinsonism and together with verbal fluency would be a useful test to support PSP diagnosis.

Magnetic Resonance Parkinsonism Index: diagnostic accuracy of a fully automated algorithm in comparison with the manual measurement in a large Italian multicentre study in patients with progressive supranuclear palsy

International Nuclear Information System (INIS)

Nigro, Salvatore; Arabia, Gennarina; Antonini, Angelo; Weis, Luca; Marcante, Andrea; Tessitore, Alessandro; Cirillo, Mario; Tedeschi, Gioacchino; Zanigni, Stefano; Tonon, Caterina; Calandra-Buonaura, Giovanna; Pezzoli, Gianni; Cilia, Roberto; Zappia, Mario; Nicoletti, Alessandra; Cicero, Calogero Edoardo; Tinazzi, Michele; Tocco, Pierluigi; Cardobi, Nicolo; Quattrone, Aldo

2017-01-01

To investigate the reliability of a new in-house automatic algorithm for calculating the Magnetic Resonance Parkinsonism Index (MRPI), in a large multicentre study population of patients affected by progressive supranuclear palsy (PSP) or Parkinson's disease (PD), and healthy controls (HC), and to compare the diagnostic accuracy of the automatic and manual MRPI values. The study included 88 PSP patients, 234 PD patients and 117 controls. MRI was performed using both 3T and 1.5T scanners. Automatic and manual MRPI values were evaluated, and accuracy of both methods in distinguishing PSP from PD and controls was calculated. No statistical differences were found between automated and manual MRPI values in all groups. The automatic MRPI values differentiated PSP from PD with an accuracy of 95 % (manual MRPI accuracy 96 %) and 97 % (manual MRPI accuracy 100 %) for 1.5T and 3T scanners, respectively. Our study showed that the new in-house automated method for MRPI calculation was highly accurate in distinguishing PSP from PD. Our automatic approach allows a widespread use of MRPI in clinical practice and in longitudinal research studies. (orig.)

Magnetic Resonance Parkinsonism Index: diagnostic accuracy of a fully automated algorithm in comparison with the manual measurement in a large Italian multicentre study in patients with progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Nigro, Salvatore [National Research Council, Institute of Bioimaging and Molecular Physiology, Catanzaro (Italy); Arabia, Gennarina [University ' ' Magna Graecia' ' , Institute of Neurology, Department of Medical and Surgical Sciences, Catanzaro (Italy); Antonini, Angelo; Weis, Luca; Marcante, Andrea [' ' Fondazione Ospedale San Camillo' ' - I.R.C.C.S, Parkinson' s Disease and Movement Disorders Unit, Venice-Lido (Italy); Tessitore, Alessandro; Cirillo, Mario; Tedeschi, Gioacchino [Second University of Naples, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Naples (Italy); Second University of Naples, MRI Research Center SUN-FISM, Naples (Italy); Zanigni, Stefano; Tonon, Caterina [Policlinico S. Orsola - Malpighi, Functional MR Unit, Bologna (Italy); University of Bologna, Department of Biomedical and Neuromotor Sciences, Bologna (Italy); Calandra-Buonaura, Giovanna [University of Bologna, Department of Biomedical and Neuromotor Sciences, Bologna (Italy); IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna (Italy); Pezzoli, Gianni; Cilia, Roberto [ASST G.Pini - CTO, ex ICP, Parkinson Institute, Milano (Italy); Zappia, Mario; Nicoletti, Alessandra; Cicero, Calogero Edoardo [University of Catania, Department ' ' G.F. Ingrassia' ' , Section of Neurosciences, Catania (Italy); Tinazzi, Michele; Tocco, Pierluigi [University Hospital of Verona, Department of Neurological and Movement Sciences, Verona (Italy); Cardobi, Nicolo [University Hospital of Verona, Institute of Radiology, Verona (Italy); Quattrone, Aldo [National Research Council, Institute of Bioimaging and Molecular Physiology, Catanzaro (Italy); University ' ' Magna Graecia' ' , Institute of Neurology, Department of Medical and Surgical Sciences, Catanzaro (Italy)

2017-06-15

To investigate the reliability of a new in-house automatic algorithm for calculating the Magnetic Resonance Parkinsonism Index (MRPI), in a large multicentre study population of patients affected by progressive supranuclear palsy (PSP) or Parkinson's disease (PD), and healthy controls (HC), and to compare the diagnostic accuracy of the automatic and manual MRPI values. The study included 88 PSP patients, 234 PD patients and 117 controls. MRI was performed using both 3T and 1.5T scanners. Automatic and manual MRPI values were evaluated, and accuracy of both methods in distinguishing PSP from PD and controls was calculated. No statistical differences were found between automated and manual MRPI values in all groups. The automatic MRPI values differentiated PSP from PD with an accuracy of 95 % (manual MRPI accuracy 96 %) and 97 % (manual MRPI accuracy 100 %) for 1.5T and 3T scanners, respectively. Our study showed that the new in-house automated method for MRPI calculation was highly accurate in distinguishing PSP from PD. Our automatic approach allows a widespread use of MRPI in clinical practice and in longitudinal research studies. (orig.)

Dsc E3 ligase localization to the Golgi requires the ATPase Cdc48 and cofactor Ufd1 for activation of sterol regulatory element-binding protein in fission yeast.

Science.gov (United States)

Burr, Risa; Ribbens, Diedre; Raychaudhuri, Sumana; Stewart, Emerson V; Ho, Jason; Espenshade, Peter J

2017-09-29

Sterol regulatory element-binding proteins (SREBPs) in the fission yeast Schizosaccharomyces pombe regulate lipid homeostasis and the hypoxic response under conditions of low sterol or oxygen availability. SREBPs are cleaved in the Golgi through the combined action of the Dsc E3 ligase complex, the rhomboid protease Rbd2, and the essential ATPases associated with diverse cellular activities (AAA + ) ATPase Cdc48. The soluble SREBP N-terminal transcription factor domain is then released into the cytosol to enter the nucleus and regulate gene expression. Previously, we reported that Cdc48 binding to Rbd2 is required for Rbd2-mediated SREBP cleavage. Here, using affinity chromatography and mass spectrometry experiments, we identified Cdc48-binding proteins in S. pombe , generating a list of many previously unknown potential Cdc48-binding partners. We show that the established Cdc48 cofactor Ufd1 is required for SREBP cleavage but does not interact with the Cdc48-Rbd2 complex. Cdc48-Ufd1 is instead required at a step prior to Rbd2 function, during Golgi localization of the Dsc E3 ligase complex. Together, these findings demonstrate that two distinct Cdc48 complexes, Cdc48-Ufd1 and Cdc48-Rbd2, are required for SREBP activation and low-oxygen adaptation in S. pombe . © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Frontal dynamic aphasia in progressive supranuclear palsy: Distinguishing between generation and fluent sequencing of novel thoughts.

Science.gov (United States)

Robinson, Gail A; Spooner, Donna; Harrison, William J

2015-10-01

Frontal dynamic aphasia is characterised by a profound reduction in spontaneous speech despite well-preserved naming, repetition and comprehension. Since Luria (1966, 1970) designated this term, two main forms of dynamic aphasia have been identified: one, a language-specific selection deficit at the level of word/sentence generation, associated with left inferior frontal lesions; and two, a domain-general impairment in generating multiple responses or connected speech, associated with more extensive bilateral frontal and/or frontostriatal damage. Both forms of dynamic aphasia have been interpreted as arising due to disturbances in early prelinguistic conceptual preparation mechanisms that are critical for language production. We investigate language-specific and domain-general accounts of dynamic aphasia and address two issues: one, whether deficits in multiple conceptual preparation mechanisms can co-occur; and two, the contribution of broader cognitive processes such as energization, the ability to initiate and sustain response generation over time, to language generation failure. Thus, we report patient WAL who presented with frontal dynamic aphasia in the context of progressive supranuclear palsy (PSP). WAL was given a series of experimental tests that showed that his dynamic aphasia was not underpinned by a language-specific deficit in selection or in microplanning. By contrast, WAL presented with a domain-general deficit in fluent sequencing of novel thoughts. The latter replicated the pattern documented in a previous PSP patient (Robinson, et al., 2006); however, unique to WAL, generating novel thoughts was impaired but there was no evidence of a sequencing deficit because perseveration was absent. Thus, WAL is the first unequivocal case to show a distinction between novel thought generation and subsequent fluent sequencing. Moreover, WAL's generation deficit encompassed verbal and non-verbal responses, showing a similar (but more profoundly reduced) pattern

Golgi protein 73 as a biomarker for hepatocellular carcinoma: A diagnostic meta-analysis.

Science.gov (United States)

Yang, Jing; Li, Jingjing; Dai, Weiqi; Wang, Fan; Shen, Miao; Chen, Kan; Cheng, Ping; Zhang, Yan; Wang, Chengfen; Zhu, Rong; Zhang, Huawei; Zheng, Yuanyuan; Wang, Junshan; Xia, Yujing; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

2015-04-01

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and the third leading cause of cancer-related mortality worldwide. Conflicting results have been reported regarding the use of serum Golgi protein 73 (GP73) as a promising serum marker for the diagnosis of HCC; therefore, the aim of the present study was to provide a systematic review of the diagnostic performance of GP73 for HCC. Following a systematic review of the relevant studies, a number of indices associated with the accuracy of the diagnostic performance of GP73, including the sensitivity and specificity, were pooled using Meta Disc 1.4 software. Data were presented as forest plots, and summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance. Eleven studies were included in this meta-analysis. The summary estimates for serum GP73 in diagnosing HCC were as follows: Sensitivity, 77% [95% confidence interval (CI), 75-79%]; specificity, 91% (95% CI, 90-92%); positive likelihood ratio, 4.34 (95% CI, 2.19-8.59); negative likelihood ratio, 0.30 (95% CI, 0.26-0.36) and diagnostic odds ratio, 15.78 (95% CI, 6.95-35.83). The area under the SROC curve was 0.8638, and the Q index was 0.7944. Significant heterogeneity was found. This meta-analysis indicates a moderate diagnostic value of GP73 in HCC; however, further studies with rigorous design, large sample size and multiregional cooperation are required.

Asparagus IRX9, IRX10, and IRX14A Are Components of an Active Xylan Backbone Synthase Complex that Forms in the Golgi Apparatus1[OPEN

Science.gov (United States)

Zeng, Wei; Picard, Kelsey L.; Song, Lili; Wu, Ai-Min; Farion, Isabela M.; Zhao, Jia; Ford, Kris; Bacic, Antony

2016-01-01

Heteroxylans are abundant components of plant cell walls and provide important raw materials for the food, pharmaceutical, and biofuel industries. A number of studies in Arabidopsis (Arabidopsis thaliana) have suggested that the IRREGULAR XYLEM9 (IRX9), IRX10, and IRX14 proteins, as well as their homologs, are involved in xylan synthesis via a Golgi-localized complex termed the xylan synthase complex (XSC). However, both the biochemical and cell biological research lags the genetic and molecular evidence. In this study, we characterized garden asparagus (Asparagus officinalis) stem xylan biosynthesis genes (AoIRX9, AoIRX9L, AoIRX10, AoIRX14A, and AoIRX14B) by heterologous expression in Nicotiana benthamiana. We reconstituted and partially purified an active XSC and showed that three proteins, AoIRX9, AoIRX10, and AoIRX14A, are necessary for xylan xylosyltranferase activity in planta. To better understand the XSC structure and its composition, we carried out coimmunoprecipitation and bimolecular fluorescence complementation analysis to show the molecular interactions between these three IRX proteins. Using a site-directed mutagenesis approach, we showed that the DxD motifs of AoIRX10 and AoIRX14A are crucial for the catalytic activity. These data provide, to our knowledge, the first lines of biochemical and cell biological evidence that AoIRX9, AoIRX10, and AoIRX14A are core components of a Golgi-localized XSC, each with distinct roles for effective heteroxylan biosynthesis. PMID:26951434

COPA mutations impair ER-Golgi transport causing hereditary autoimmune-mediated lung disease and arthritis

Science.gov (United States)

Watkin, Levi B.; Jessen, Birthe; Wiszniewski, Wojciech; Vece, Timothy; Jan, Max; Sha, Youbao; Thamsen, Maike; Santos-Cortez, Regie L. P.; Lee, Kwanghyuk; Gambin, Tomasz; Forbes, Lisa; Law, Christopher S.; Stray-Petersen, Asbjørg; Cheng, Mickie H.; Mace, Emily M.; Anderson, Mark S.; Liu, Dongfang; Tang, Ling Fung; Nicholas, Sarah K.; Nahmod, Karen; Makedonas, George; Canter, Debra; Kwok, Pui-Yan; Hicks, John; Jones, Kirk D.; Penney, Samantha; Jhangiani, Shalini N.; Rosenblum, Michael D.; Dell, Sharon D.; Waterfield, Michael R.; Papa, Feroz R.; Muzny, Donna M.; Zaitlen, Noah; Leal, Suzanne M.; Gonzaga-Jauregui, Claudia; Boerwinkle, Eric; Eissa, N. Tony; Gibbs, Richard A.; Lupski, James R.; Orange, Jordan S.; Shum, Anthony K.

2015-01-01

Advances in genomics have allowed unbiased genetic studies of human disease with unexpected insights into the molecular mechanisms of cellular immunity and autoimmunity1. We performed whole exome sequencing (WES) and targeted sequencing in patients with an apparent Mendelian syndrome of autoimmune disease characterized by high-titer autoantibodies, inflammatory arthritis and interstitial lung disease (ILD). In five families, we identified four unique deleterious variants in the Coatomer subunit alpha (COPA) gene all located within the same functional domain. We hypothesized that mutant COPA leads to a defect in intracellular transport mediated by coat protein complex I (COPI)2–4. We show that COPA variants impair binding of proteins targeted for retrograde Golgi to ER transport and demonstrate that expression of mutant COPA leads to ER stress and the upregulation of Th17 priming cytokines. Consistent with this pattern of cytokine expression, patients demonstrated a significant skewing of CD4+ T cells toward a T helper 17 (Th17) phenotype, an effector T cell population implicated in autoimmunity5,6. Our findings uncover an unexpected molecular link between a vesicular transport protein and a syndrome of autoimmunity manifested by lung and joint disease. These findings provide a unique opportunity to understand how alterations in cellular homeostasis caused by a defect in the intracellular trafficking pathway leads to the generation of human autoimmune disease. PMID:25894502

Hsp47 and cyclophilin B traverse the endoplasmic reticulum with procollagen into pre-Golgi intermediate vesicles. A role for Hsp47 and cyclophilin B in the export of procollagen from the endoplasmic reticulum.

Science.gov (United States)

Smith, T; Ferreira, L R; Hebert, C; Norris, K; Sauk, J J

1995-08-04

Hsp47 and cyclophilin B (CyPB) are residents of the endoplasmic reticulum (ER). Both of these proteins are closely associated with polysome-associated alpha 1(I) procollagen chains. Hsp47 possesses chaperone properties early during the translation of procollagen while the cis/trans-isomerase properties of CyPB facilitate procollagen folding. In this report, we further investigate the interaction of these proteins with procollagen I during export from the ER. To inhibit vesicular budding and retain procollagen within the ER, cells were treated with the heterotrimeric G protein inhibitor mastoparan or calphostin C, a specific inhibitor of diacylglycerol/phorbol ester binding proteins. To arrest procollagen in pre-Golgi intermediate vesicles, cells were treated with guanosine 5'-3-O-(thio)triphosphate. Pulse-chase experiments of cells labeled with [35S]methionine followed by immunoprecipitation during the chase period with anti-procollagen, anti-Hsp47, and anti-CyPB antibodies were performed to reveal the relationship between Hsp47/CyPB/procollagen I. The distribution of procollagen, Hsp47, and CyPB to the ER and/or pre-Golgi vesicles was verified by immunofluorescence. Hsp47 and CyPB remained associated with procollagen retained within the ER. Hsp47 and CyPB were also associated with procollagen exported from the ER into pre-Golgi intermediate vesicles. Treatment of cells with cyclosporin A diminished the levels of CyPB bound to procollagen and diminished the rate of Hsp47 released from procollagen and the rate of procollagen secretion, suggesting that Hsp47 release from procollagen may be driven by helix formation. Also, these studies suggest that Hsp47 may resemble protein disulfide isomerase and possess both chaperone and anti-chaperone properties. During translation, high levels of Hsp47 are seen to limit protein aggregation and facilitate chain registration. Later, Hsp47 and/or CyPB and protein disulfide isomerase act as anti-chaperones and provide the basis for

Sites of sulfate incorporation into mammotrophs and somatotrophs of the rat pituitary as determined by quantitative electron microscopic autoradiography

International Nuclear Information System (INIS)

Rosenzweig, L.J.; Farquhar, M.G.

1980-01-01

Dispersed pituitary cells were labeled with [ 35 S]sulfate followed by a chase incubation in order to study sulfate incorporation and transport in anterior pituitary cells. The initial site of incorporation of sulfate, the kinetics of sulfate transport, and the intracellular localization of incorporated sulfate were studied by quantitative electron microscope autoradiography. Analysis of autoradiograms from estrogen-treated female rats revealed that all granulated cell types incorporate sulfate. The labeling index of the various cell types was greatest for mammotrophs, slightly less for corticotrophs, gonadotrophs, and thyrotrophs and least for somatotrophs. These results indicate the [ 35 S]sulfate is initially incorporated into the Golgi complex of all interior pituitary cell types. The majority of the sulfate-labeled macromolecules are then packaged into immature secretion granules in the Golgi region, which become mature granules. In addition, a considerable amount (approx. 30% in mammotrophs) of the radioactivity remains associated within the Golgi region for up to 2 h post pulse. The incorporation of sulfate into the Golgi complex and its transfer to secretory granule membranes and/or contents thus appears to be a general property of anterior pituitary cells

Use of [/sup 99m/Tc]-HM-PAO in the diagnosis of primary degenerative dementia

International Nuclear Information System (INIS)

Testa, H.J.; Snowden, J.S.; Neary, D.; Shields, R.A.; Burjan, A.W.; Prescott, M.C.; Northen, B.; Goulding, P.

1988-01-01

The clinical value of single photon emission computed tomography (SPECT) in the differential diagnosis of dementia due to cerebral atrophy was evaluated by comparing the pattern of distribution [/sup 99m/Tc]-HM-PAO in three dementing conditions. Imaging was carried out in 26 patients with suspected Alzheimer's disease, 14 with dementia of the frontal-lobe type, and 13 with progressive supranuclear palsy. Images were evaluated and reported without knowledge of clinical diagnosis with respect to regions of reduced uptake of tracer. Reduced uptake in the posterior cerebral hemispheres was characteristic of Alzheimer's disease, while selective anterior hemisphere abnormalities characterized both dementia of the frontal-lobe type and progressive supranuclear palsy. The latter conditions could be distinguished on the basis of the appearance of integrity of the rim of the frontal cortex. The technique has an important role in the differentiation of degenerative dementias

Layer 6 cortical neurons require Reelin-Dab1 signaling for cellular orientation, Golgi deployment, and directed neurite growth into the marginal zone.

Science.gov (United States)

O'Dell, Ryan S; Ustine, Candida J M; Cameron, David A; Lawless, Sean M; Williams, Rebecca M; Zipfel, Warren R; Olson, Eric C

2012-07-07

The secreted ligand Reelin is believed to regulate the translocation of prospective layer 6 (L6) neocortical neurons into the preplate, a loose layer of pioneer neurons that overlies the ventricular zone. Recent studies have also suggested that Reelin controls neuronal orientation and polarized dendritic growth during this period of early cortical development. To explicitly characterize and quantify how Reelin controls this critical aspect of neurite initiation and growth we used a new ex utero explant model of early cortical development to selectively label a subset of L6 cortical neurons for complete 3-D reconstruction. The total neurite arbor sizes of neurons in Reelin-deficient (reeler mutant) and Dab1-deficient (Reelin-non-responsive scrambler mutant) cortices were quantified and unexpectedly were not different than control arbor lengths (p = 0.51). For each mutant, however, arbor organization was markedly different: mutant neurons manifested more primary processes (neurites emitted directly from the soma) than wild type, and these neurites were longer and displayed less branching. Reeler and scrambler mutant neurites extended tangentially rather than radially, and the Golgi apparatus that normally invests the apical neurite was compact in both reeler and scrambler mutants. Mutant cortices also exhibited a neurite "exclusion zone" which was relatively devoid of L6 neuron neurites and extended at least 15 μm beneath the pial surface, an area corresponding to the marginal zone (MZ) in the wild type explants. The presence of an exclusion zone was also indicated in the orientation of mutant primary neurite and neuronal somata, which failed to adopt angles within ~20˚ of the radial line to the pial surface. Injection of recombinant Reelin to reeler, but not scrambler, mutant cortices fully rescued soma orientation, Golgi organization, and dendritic projection defects within four hrs. These findings indicate Reelin promotes directional dendritic growth into

Papel del diacilglicerol en el tráfico de membranas en la zona entre el retículo endoplasmático y el complejo de Golgi, El

OpenAIRE

Fernández Ulibarri, Inés

2008-01-01

DE LA TESIS:El DAG es esencial para formar los intermediarios de transporte que se dirigen a la membrana plasmática. Sin embargo, no existen evidencias de su posible participación en las etapas tempranas de la vía secretora. Por tanto, nos centramos en averiguar la implicación del DAG en el transporte de proteínas en la zona del ER/Golgi. Para ello, utilizamos una variedad de fármacos conocidos que inhiben las enzimas responsables de la producción del DAG. Nuestros datos indican que el DAG es...

El Papel del diacilglicerol en el tráfico de membranas en la zona entre el retículo endoplasmático y el complejo de Golgi

OpenAIRE

Fernández Ulibarri, Inés

2008-01-01

[spa] DE LA TESIS: El DAG es esencial para formar los intermediarios de transporte que se dirigen a la membrana plasmática. Sin embargo, no existen evidencias de su posible participación en las etapas tempranas de la vía secretora. Por tanto, nos centramos en averiguar la implicación del DAG en el transporte de proteínas en la zona del ER/Golgi. Para ello, utilizamos una variedad de fármacos conocidos que inhiben las enzimas responsables de la producción del DAG. Nuestros datos indican que el...

Iodine 123-labeled meta-iodobenzylguanidine myocardial scintigraphy in the cases of idiopathic Parkinson`s disease, multiple system atrophy, and progressive supranuclear palsy

Energy Technology Data Exchange (ETDEWEB)

Yoshita, Mitsuhiro; Hayashi, Michiyuki; Hirai, Shunsaku [Tokyo Metropolitan Neurological Hospital (Japan)

1997-06-01

To investigate cardiac sympathetic function in Parkinson`s disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP), {sup 123}I-MIBG myocardial scintigraphy was performed in 25 patients with PD, 25 patients with MSA, 14 patients with PSP, and 20 control subjects. In planar imaging studies, the heart-to-mediastinum average count ratio (H/M) was calculated for both early and delayed images. The mean value of H/M in patients with PD was significantly lower than in those with MSA, PSP, or no disease. Regardless of disease severity or intensity of anti-parkinsonian pharmacotherapy, mean values for H/M were always low in patients with PD. The mean values of H/M in patients with MSA and PSP were significantly lower than in controls. There was no significant difference between the mean value of H/M in MSA with orthostatic hypotension (OH) and that in MSA without OH, and also there was no significant difference between the mean value of H/M in MSA with striatonigral degeneration and that in MSA with olivopontocerebellar atrophy. Although the mean value of H/M in PSP with amitriptyline treatment was significantly lower than that in PSP patients without amitriptyline treatment, there was no significant difference between the mean value of H/M in PSP patients without amitriptyline treatment and that in controls. There was no correlation between H/M and disease duration in those three akinetic-rigid disorders that we have studied here. Thus, PD may have an abnormality of cardiac sympathetic function which has not been detected by previous cardiovascular autonomic studies. Particularly in early stages, {sup 123}I-MIBG myocardial scintigraphy may help to differentiate PD from MSA and PSP. (K.H.)

A lectin histochemical study to detect variation in glycosylation at the feto-maternal interface in three interbreeding equine species.

Science.gov (United States)

Jones, Carolyn J P; Allen, W R Twink; Wilsher, Sandra

2017-10-01

In this study, we compare glycosylation at the fetomaternal interface in 3 equine species: horse, donkey and zebra, all of which can interbreed to produce hybrids, to assess their glycan similarities and differences. Sections cut from 3 specimens of horse (Equus caballus) placenta (50, 200 and 280 days gestation), one donkey (Equus asinus) placenta (65 cm crown-rump length) and 5 specimens of zebra (Equus quagga) placentae (81-239 days gestation) were stained with a panel of 24 biotinylated lectins using an avidin-peroxidase revealing system. There were only slight quantitative differences in the lectin histochemistry at the feto-maternal interface between all three specimens; zebra placentae expressed more α2,6-linked sialic acid, with α1,2fucosyl residues at the microvillous interface. However, zebra trophoblast showed histological differences from the other two species, with polarised cells, prominent supranuclear Golgi bodies, and fewer intracellular granules. Our findings appear to confirm the hypothesis that closely related, interbreeding species with epitheliochorial placentae express similar glycans at the feto-maternal interface, thereby supporting the existence of a placental glycocode. We also observed intraspecies evolutionary diversion to be associated with a different histological architecture and the absence of significant intracellular granules. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of a magnetic particles-based chemiluminescence enzyme immunoassay for Golgi protein 73 in human serum.

Science.gov (United States)

Liu, Xiangyi; Wan, Xiaohua; Lu, Sheng; Zhang, Lijun; Yu, Shaohua; Lu, Xinxin

2015-05-20

Golgi protein 73 (GP73) is regarded as a potential serum biomarker for early diagnosis of hepatocellular carcinoma (HCC). We developed a rapid magnetic particles-based chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of serum GP73. Fluorescein isothiocyanate (FITC) and alkaline phosphatase (ALP) were used to label 2 different monoclonal antibodies to GP73. Serum GP73 was captured with labeled antibodies and formed a sandwiched immunoreaction. The magnetic particles (MPs) coated with anti-FITC antibody were used as a means of separation of the GP73 protein from other serum proteins. After adding the enzyme substrate solution, the relative light unit (RLU) was measured. A MPs-CLEIA for serum GP73 was established and evaluated. The RLU was directly proportional to the concentration of GP73. The method linearity was 5-600 μg/l. Limit of the blank was 2.19 μg/l. The intra- and inter-assay imprecision was 73-0.89), and the sensitivity and specificity, with cut-off value of 115.6 μg/l, were 75.4% and 92.1%, respectively. The proposed method demonstrates an acceptable performance for quantifying serum GP73. This assay could be appropriate for routine use in clinical laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

Upper midbrain profile sign and cingulate sulcus sign. MRI findings on sagittal images in idiopathic normal-pressure hydrocephalus, Alzheimer's disease, and progressive supranuclear palsy

International Nuclear Information System (INIS)

Adachi, Michito; Ohshima, Fumi; Kawanami, Toru; Kato, Takeo

2006-01-01

On magnetic resonance imaging (MRI) sagittal sections, we sometimes encounter abnormal aspects of the superior profile of the midbrain and the cingulate sulcus in patients with dementia. In this preliminary study, we refer to these findings as the ''upper midbrain profile sign'' and the cingulate sulcus sign.'' We prospectively evaluated the usefulness of these signs for the diagnosis of idiopathic normal-pressure hydrocephalus (iNPH), Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). We evaluated the upper midbrain profile sign and the cingulate sulcus sign on MRI sagittal images obtained from 21 people with headaches but no neurological deficit (controls), 10 iNPH patients, 11 AD patients, and 5 PSP patients. The upper midbrain profile sign indicated a concave shape to the superior profile of the midbrain on mid-sagittal images, and the cingulate sulcus sign indicated a narrow, tight aspect of the posterior part of the cingulate sulcus on paramedian-sagittal images. These signs were never seen in any images from the controls. The upper midbrain profile sign was seen in 7 of 10 patients with iNPH, 5 of 11 with AD, and 3 of 5 with PSP. The cingulate sulcus sign was seen in all 10 patients with iNPH but was never seen in any patient with AD or PSP. The upper midbrain profile sign could support a diagnosis of PSP but cannot discriminate among iNPH, AD, and PSP. In contrast, the cingulate sulcus sign has a very high sensitivity for iNPH and should facilitate the distinction of iNPH from other dementias. In the clinical setting, it is momentous to evaluate these signs easily by one simple MRI sequence. (author)

TFG facilitates outer coat disassembly on COPII transport carriers to promote tethering and fusion with ER-Golgi intermediate compartments.

Science.gov (United States)

Hanna, Michael G; Block, Samuel; Frankel, E B; Hou, Feng; Johnson, Adam; Yuan, Lin; Knight, Gavin; Moresco, James J; Yates, John R; Ashton, Randolph; Schekman, Randy; Tong, Yufeng; Audhya, Anjon

2017-09-12

The conserved coat protein complex II (COPII) mediates the initial steps of secretory protein trafficking by assembling onto subdomains of the endoplasmic reticulum (ER) in two layers to generate cargo-laden transport carriers that ultimately fuse with an adjacent ER-Golgi intermediate compartment (ERGIC). Here, we demonstrate that Trk-fused gene (TFG) binds directly to the inner layer of the COPII coat. Specifically, the TFG C terminus interacts with Sec23 through a shared interface with the outer COPII coat and the cargo receptor Tango1/cTAGE5. Our findings indicate that TFG binding to Sec23 outcompetes these other associations in a concentration-dependent manner and ultimately promotes outer coat dissociation. Additionally, we demonstrate that TFG tethers vesicles harboring the inner COPII coat, which contributes to their clustering between the ER and ERGIC in cells. Together, our studies define a mechanism by which COPII transport carriers are retained locally at the ER/ERGIC interface after outer coat disassembly, which is a prerequisite for fusion with ERGIC membranes.

Different patterns of motor activity induce differential plastic changes in pyramidal neurons in the motor cortex of rats: A Golgi study.

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Vázquez-Hernández, Nallely; González-Tapia, Diana C; Martínez-Torres, Nestor I; González-Tapia, David; González-Burgos, Ignacio

2017-09-14

Rehabilitation is a process which favors recovery after brain damage involving motor systems, and neural plasticity is the only real resource the brain has for inducing neurobiological events in order to bring about re-adaptation. Rats were placed on a treadmill and made to walk, in different groups, at different velocities and with varying degrees of inclination. Plastic changes in the spines of the apical and basal dendrites of fifth-layer pyramidal neurons in the motor cortices of the rats were detected after study with the Golgi method. Numbers of dendritic spines increased in the three experimental groups, and thin, mushroom, stubby, wide, and branched spines increased or decreased in proportion depending on the motor demands made of each group. Along with the numerical increase of spines, the present findings provide evidence that dendritic spines' geometrical plasticity is involved in the differential performance of motor activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Golgi protein 73 versus alpha-fetoprotein as a biomarker for hepatocellular carcinoma: a diagnostic meta- analysis

International Nuclear Information System (INIS)

Zhou, Ying; Yin, Xin; Ying, Jun; Zhang, BoHeng

2012-01-01

There have been conflicting reports about serum golgi protein 73 (GP73) as one of the most promising serum markers for the diagnosis of hepatocellular carcinoma (HCC). This study was to make a systematic review about the diagnostic accuracy of serum GP73 versus alpha-fetoprotein (AFP) for HCC. After a systematic review of related studies, sensitivity, specificity and other measures about the accuracy of serum GP73 and AFP in the diagnosis of HCC were pooled using random-effects models. Summary receiver operating characteristic curve analysis was used to summarize the overall test performance. Eight studies were included in our meta-analysis. The summary estimates for serum GP73 and AFP in diagnosing HCC in the studies included were as follows: sensitivity, 76% (95% confidence interval (CI) 51-91%) vs. 70% (47-86%); specificity, 86% (95%CI 65-95%) vs. 89% (69-96%); diagnostic odds ratio (DOR), 18.59 (95%CI 5.33-64.91) vs. 18.00(9.41-34.46); and area under sROC, 0.88 (95%CI 0.77-0.99) vs. 0.86 (95%CI 0.84-0.87). The current evidence indicates that serum GP73 has a comparable accuracy to AFP for the diagnosis of HCC, while the value of serum GP73 in combination with AFP for HCC detection deserves further investigation

GOLGA2/GM130, cis-Golgi matrix protein, is a novel target of anticancer gene therapy.

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Chang, Seung-Hee; Hong, Seong-Ho; Jiang, Hu-Lin; Minai-Tehrani, Arash; Yu, Kyeong-Nam; Lee, Jae-Ho; Kim, Ji-Eun; Shin, Ji-Young; Kang, Bitna; Park, Sungjin; Han, Kiwon; Chae, Chanhee; Cho, Myung-Haing

2012-11-01

Achievement of long-term survival of patients with lung cancer treated with conventional chemotherapy is still difficult for treatment of metastatic and advanced tumors. Despite recent progress in investigational therapies, survival rates are still disappointingly low and novel adjuvant and systemic therapies are urgently needed. A recently elucidated secretory pathway is attracting considerable interest as a promising anticancer target. The cis-Golgi matrix protein, GOLGA2/GM130, plays an important role in glycosylation and transport of protein in the secretory pathway. In this study, the effects of short hairpin RNA (shRNA) constructs targeting GOLGA2/GM130 (shGOLGA2) on autophagy and lung cancer growth were evaluated in vitro and in vivo. Downregulation of GOLGA2/GM130 led to induction of autophagy and inhibition of glycosylation in A549 cells and in the lungs of K-ras(LA1) mice. Furthermore, downregulation of GOLGA2/GM130 decreased angiogenesis and cancer cell invasion in vitro and suppressed tumorigenesis in lung cancer mice model. The tumor specificity of sequence targeting GOLGA2/GM130 was also demonstrated. Taken together, these results suggest that induction of autophagy by shGOLGA2 may induce cell death rather than cell survival. Therefore, downregulation of GOLGA2/GM130 may be a potential therapeutic option for lung cancer.

The Golgi localization of phosphatidylinositol transfer protein beta requires the protein kinase C-dependent phosphorylation of serine 262 and is essential for maintaining plasma membrane sphingomyelin levels.

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van Tiel, Claudia M; Westerman, Jan; Paasman, Marten A; Hoebens, Martha M; Wirtz, Karel W A; Snoek, Gerry T

2002-06-21

Recombinant mouse phosphatidylinositol transfer protein (PI-TP)beta is a substrate for protein kinase C (PKC)-dependent phosphorylation in vitro. Based on site-directed mutagenesis and two-dimensional tryptic peptide mapping, Ser(262) was identified as the major site of phosphorylation and Ser(165) as a minor phosphorylation site. The phospholipid transfer activities of wild-type PI-TP beta and PI-TP beta(S262A) were identical, whereas PI-TP beta(S165A) was completely inactive. PKC-dependent phosphorylation of Ser(262) also had no effect on the transfer activity of PI-TP beta. To investigate the role of Ser(262) in the functioning of PI-TP beta, wtPI-TP beta and PI-TP beta(S262A) were overexpressed in NIH3T3 fibroblast cells. Two-dimensional PAGE analysis of cell lysates was used to separate PI-TP beta from its phosphorylated form. After Western blotting, wtPI-TP beta was found to be 85% phosphorylated, whereas PI-TP beta(S262A) was not phosphorylated. In the presence of the PKC inhibitor GF 109203X, the phosphorylated form of wtPI-TP beta was strongly reduced. Immunolocalization showed that wtPI-TP beta was predominantly associated with the Golgi membranes. In the presence of the PKC inhibitor, wtPI-TP beta was distributed throughout the cell similar to what was observed for PI-TP beta(S262A). In contrast to wtPI-TP beta overexpressors, cells overexpressing PI-TP beta(S262A) were unable to rapidly replenish sphingomyelin in the plasma membrane upon degradation by sphingomyelinase. This implies that PKC-dependent association with the Golgi complex is a prerequisite for PI-TP beta to express its effect on sphingomyelin metabolism.

A golgi study of the optic tectum of the tegu lizard, Tupinambis nigropunctatus.

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Butler, A B; Ebbesson, O E

1975-06-01

The dendritic patterns of cells in the optic tectum of the tegu lizard, Tupinambis nigropunctatus, were analyzed with the Ramon-Moliner modification of the Golgi-Cox technique. Cell types were compared with those described by other authors in the tectum of other reptiles; particular comparisons of our results were made with the description of cell types in the chameleon (Ramń, 1896), as the latter is the most complete analysis in the literature. The periventricular gray layers 3 and 5 consist primarily of two cell types--piriform or pyramidal shaped cells and horizontal cells. Cells in the medial portion of the tectum, in an area coextensive with the bilateral spinal projection zone, possess dendrites that extend across the midline. The latter cells have either fusiform or pyramidal shaped somas. The central white zone, layer 6, contains fibers, large fusiform or pyramidal shaped cells, fusiform cells, and small horizontal cells. The central gray zone, layer 7, is composed predominately of fusiform cells which have dendrites extending to the superficial optic layers, large polygonal cells, and horizontal cells. The superficial gray and white layers, layers 8-13, contain polygonal, fusiform, stellate, and horizontal elements. Layer 14 is composed solely of afferent optic tract fibers. Several differences in the occurrence and distribution of cell types between the tegu and the other reptiles studied are noted. Additionally, the laminar distribution of retinal, tectotectal, telencephalic, and spinal projections in the tegutectum can be related to the distribution of cell types, and those cells which may be postsynaptic to specific inputs can be identified. The highly differentiated laminar structure of the reptilian optic tectum, both in regard to cell type and to afferent and efferent connections, may serve as a model for studying some functional properties of lamination common to cortical structures.

Serum Golgi protein 73 is a prognostic rather than diagnostic marker in hepatocellular carcinoma.

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Dong, Min; Chen, Zhan-Hong; Li, Xing; Li, Xiao-Yun; Wen, Jing-Yun; Lin, Qu; Ma, Xiao-Kun; Wei, Li; Chen, Jie; Ruan, Dan-Yun; Lin, Ze-Xiao; Wang, Tian-Tian; Wu, Dong-Hao; Wu, Xiang-Yuan

2017-11-01

Serum Golgi protein 73 (sGP73) is a candidate diagnostic biomarker for hepatocellular carcinoma (HCC). However, current evidence of its diagnostic value is conflicting, primarily due to the small sample sizes of previous studies, and its prognostic role in HCC also remains unclear. In the present study, sGP73 levels in 462 patients with HCC, 186 patients with liver cirrhosis, and 83 healthy controls were evaluated using ELISA, and it was identified that the median sGP73 levels were significantly higher in the HCC (18.7 ng/ml) and liver cirrhosis (18.5 ng/ml) patients than in the healthy controls (0 ng/ml; both P<0.001); however, the levels did not significantly differ between the HCC and liver cirrhosis groups (P=0.632). sGP73 had an inferior sensitivity and specificity for HCC diagnosis (27.79 and 77.96%, respectively) compared with α-fetoprotein (57.36 and 90.96%, respectively; P<0.001). In the HCC group, a high level of sGP73 was associated with aggressive clinicopathological features and independently predicted poor overall survival (OS) time (P<0.001). Additionally, in patients with resectable HCC, a high level of sGP73 was associated with significantly decreased disease-free survival (P<0.001) and OS (P=0.039) times compared with a low level of sGP73. This study demonstrated that sGP73 is unsuitable as a diagnostic marker for the early detection of HCC; however, it is an independent negative prognostic marker, providing a novel risk stratification factor and a potential therapeutic molecular target for HCC.

Diffusion tensor imaging differentiates vascular parkinsonism from parkinsonian syndromes of degenerative origin in elderly subjects

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Deverdun, Jérémy [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Laboratoire Charles Coulomb, CNRS UMR 5221 - Université Montpellier II, Montpellier (France); I2FH, Institut d’Imagerie Fonctionnelle Humaine, Hôpital Gui de Chauliac, CHRU de, Montpellier (France); Menjot de Champfleur, Sophie [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Clinique du Parc, Castelnau-le-Lez (France); Cabello-Aguilar, Simon [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); I2FH, Institut d’Imagerie Fonctionnelle Humaine, Hôpital Gui de Chauliac, CHRU de, Montpellier (France); Maury, Florence [Department of Neurology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Molino, François [Laboratoire Charles Coulomb, CNRS UMR 5221 - Université Montpellier II, Montpellier (France); Institut de Génomique Fonctionnelle, UMR 5203 - INSERM U661 - Université Montpellier II - Université, Montpellier I (France); Charif, Mahmoud [Department of Neurology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Leboucq, Nicolas [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Ayrignac, Xavier; Labauge, Pierre [Department of Neurology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); and others

2014-11-15

Background and Purpose: The etiologic diagnosis of parkinsonian syndromes is of particular importance when considering syndromes of vascular or degenerative origin. The purpose of this study is to find differences in the white-matter architecture between those two groups in elderly patients. Materials and Methods: Thirty-five patients were prospectively included (multiple-system atrophy, n = 5; Parkinson's disease, n = 15; progressive supranuclear palsy, n = 9; vascular parkinsonism, n = 6), with a mean age of 76 years. Patients with multiple-system atrophy, progressive supranuclear palsy and Parkinson's disease were grouped as having parkinsonian syndromes of degenerative origin. Brain MRIs included diffusion tensor imaging. Fractional anisotropy and mean-diffusivity maps were spatially normalized, and group analyses between parkinsonian syndromes of degenerative origin and vascular parkinsonism were performed using a voxel-based approach. Results: Statistical parametric-mapping analysis of diffusion tensor imaging data showed decreased fractional anisotropy value in internal capsules bilaterally in patients with vascular parkinsonism compared to parkinsonian syndromes of degenerative origin (p = 0.001) and showed a lower mean diffusivity in the white matter of the left superior parietal lobule (p = 0.01). Fractional anisotropy values were found decreased in the middle cerebellar peduncles in multiple-system atrophy compared to Parkinson's disease and progressive supranuclear palsy. The mean diffusivity was increased in those regions for these subgroups. Conclusion: Clinically defined vascular parkinsonism was associated with decreased fractional anisotropy in the deep white matter (internal capsules) compared to parkinsonian syndromes of degenerative origin. These findings are consistent with previously published neuropathological data.

Diffusion tensor imaging differentiates vascular parkinsonism from parkinsonian syndromes of degenerative origin in elderly subjects

International Nuclear Information System (INIS)

Deverdun, Jérémy; Menjot de Champfleur, Sophie; Cabello-Aguilar, Simon; Maury, Florence; Molino, François; Charif, Mahmoud; Leboucq, Nicolas; Ayrignac, Xavier; Labauge, Pierre

2014-01-01

Background and Purpose: The etiologic diagnosis of parkinsonian syndromes is of particular importance when considering syndromes of vascular or degenerative origin. The purpose of this study is to find differences in the white-matter architecture between those two groups in elderly patients. Materials and Methods: Thirty-five patients were prospectively included (multiple-system atrophy, n = 5; Parkinson's disease, n = 15; progressive supranuclear palsy, n = 9; vascular parkinsonism, n = 6), with a mean age of 76 years. Patients with multiple-system atrophy, progressive supranuclear palsy and Parkinson's disease were grouped as having parkinsonian syndromes of degenerative origin. Brain MRIs included diffusion tensor imaging. Fractional anisotropy and mean-diffusivity maps were spatially normalized, and group analyses between parkinsonian syndromes of degenerative origin and vascular parkinsonism were performed using a voxel-based approach. Results: Statistical parametric-mapping analysis of diffusion tensor imaging data showed decreased fractional anisotropy value in internal capsules bilaterally in patients with vascular parkinsonism compared to parkinsonian syndromes of degenerative origin (p = 0.001) and showed a lower mean diffusivity in the white matter of the left superior parietal lobule (p = 0.01). Fractional anisotropy values were found decreased in the middle cerebellar peduncles in multiple-system atrophy compared to Parkinson's disease and progressive supranuclear palsy. The mean diffusivity was increased in those regions for these subgroups. Conclusion: Clinically defined vascular parkinsonism was associated with decreased fractional anisotropy in the deep white matter (internal capsules) compared to parkinsonian syndromes of degenerative origin. These findings are consistent with previously published neuropathological data

Algorithm of Golgi protein 73 and liver stiffness accurately diagnoses significant fibrosis in chronic HBV infection.

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Cao, Zhujun; Li, Ziqiang; Wang, Hui; Liu, Yuhan; Xu, Yumin; Mo, Ruidong; Ren, Peipei; Chen, Lichang; Lu, Jie; Li, Hong; Zhuang, Yan; Liu, Yunye; Wang, Xiaolin; Zhao, Gangde; Tang, Weiliang; Xiang, Xiaogang; Cai, Wei; Liu, Longgen; Bao, Shisan; Xie, Qing

2017-11-01

Serum Golgi protein 73 (GP73) is a potential biomarker for fibrosis assessment. We aimed to develop an algorithm based on GP73 and liver stiffness (LS) for further improvement of accuracy for significant fibrosis in patients with antiviral-naïve chronic hepatitis B virus (HBV) infection. Diagnostic accuracy evaluation of GP73 and development of GP73-LS algorithm was performed in training cohort (n = 267) with an independent cohort (n = 133) for validation. A stepwise increasing pattern of serum GP73 was observed across fibrosis stages in patients with antiviral-naïve chronic HBV infection. Serum GP73 significantly correlated (rho = 0.48, P 73, accuracy: 63.6%). Using GP73-LS algorithm, GP73 < 63 in agreement with LS < 8.5 provided accuracy of 81.7% to excluded significant fibrosis. GP73 ≥ 63 in agreement with LS ≥ 8.5 provided accuracy of 93.3% to confirm significant fibrosis. Almost 64% or 68% of patients in the training or validation cohort could be accurately classified. Serum GP73 is a robust biomarker for significant fibrosis diagnosis. GP73-LS algorithm provided better diagnostic accuracy than currently available approaches. More than 60% antiviral naïve CHB patients could use this algorithm without resorting to liver biopsy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Violacein induces death of resistant leukaemia cells via kinome reprogramming, endoplasmic reticulum stress and Golgi apparatus collapse.

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Karla C S Queiroz

Full Text Available It is now generally recognised that different modes of programmed cell death (PCD are intimately linked to the cancerous process. However, the mechanism of PCD involved in cancer chemoprevention is much less clear and may be different between types of chemopreventive agents and tumour cell types involved. Therefore, from a pharmacological view, it is crucial during the earlier steps of drug development to define the cellular specificity of the candidate as well as its capacity to bypass dysfunctional tumoral signalling pathways providing insensitivity to death stimuli. Studying the cytotoxic effects of violacein, an antibiotic dihydro-indolone synthesised by an Amazon river Chromobacterium, we observed that death induced in CD34(+/c-Kit(+/P-glycoprotein(+/MRP1(+ TF1 leukaemia progenitor cells is not mediated by apoptosis and/or autophagy, since biomarkers of both types of cell death were not significantly affected by this compound. To clarify the working mechanism of violacein, we performed kinome profiling using peptide arrays to yield comprehensive descriptions of cellular kinase activities. Pro-death activity of violacein is actually carried out by inhibition of calpain and DAPK1 and activation of PKA, AKT and PDK, followed by structural changes caused by endoplasmic reticulum stress and Golgi apparatus collapse, leading to cellular demise. Our results demonstrate that violacein induces kinome reprogramming, overcoming death signaling dysfunctions of intrinsically resistant human leukaemia cells.

The cyclic nucleotide gated cation channel AtCNGC10 traffics from the ER via Golgi vesicles to the plasma membrane of Arabidopsis root and leaf cells

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Andres Marilou A

2007-09-01

Full Text Available Abstract Background The cyclic nucleotide-gated ion channels (CNGCs maintain cation homeostasis essential for a wide range of physiological processes in plant cells. However, the precise subcellular locations and trafficking of these membrane proteins are poorly understood. This is further complicated by a general deficiency of information about targeting pathways of membrane proteins in plants. To investigate CNGC trafficking and localization, we have measured Atcngc5 and Atcngc10 expression in roots and leaves, analyzed AtCNGC10-GFP fusions transiently expressed in protoplasts, and conducted immunofluorescence labeling of protoplasts and immunoelectron microscopic analysis of high pressure frozen leaves and roots. Results AtCNGC10 mRNA and protein levels were 2.5-fold higher in roots than leaves, while AtCNGC5 mRNA and protein levels were nearly equal in these tissues. The AtCNGC10-EGFP fusion was targeted to the plasma membrane in leaf protoplasts, and lightly labeled several intracellular structures. Immunofluorescence microscopy with affinity purified CNGC-specific antisera indicated that AtCNGC5 and AtCNGC10 are present in the plasma membrane of protoplasts. Immunoelectron microscopy demonstrated that AtCNGC10 was associated with the plasma membrane of mesophyll, palisade parenchyma and epidermal cells of leaves, and the meristem, columella and cap cells of roots. AtCNCG10 was also observed in the endoplasmic reticulum and Golgi cisternae and vesicles of 50–150 nm in size. Patch clamp assays of an AtCNGC10-GFP fusion expressed in HEK293 cells measured significant cation currents. Conclusion AtCNGC5 and AtCNGC10 are plasma membrane proteins. We postulate that AtCNGC10 traffics from the endoplasmic reticulum via the Golgi apparatus and associated vesicles to the plasma membrane. The presence of the cation channel, AtCNGC10, in root cap meristem cells, cell plate, and gravity-sensing columella cells, combined with the previously reported

Progressive Supranuclear Palsy

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... Disorders (NORD) 55 Kenosia Avenue Danbury, CT 06810 orphan@rarediseases.org https://rarediseases.org/ Tel: 203-744- ... Overview Loan Repayment Programs Administrative Supplements Peer Review Process Review Committees Application Support Library Clinical Research Next ...

Unusual armadillo fold in the human general vesicular transport factor p115.

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Harald Striegl

Full Text Available The golgin family gives identity and structure to the Golgi apparatus and is part of a complex protein network at the Golgi membrane. The golgin p115 is targeted by the GTPase Rab1a, contains a large globular head region and a long region of coiled-coil which forms an extended rod-like structure. p115 serves as vesicle tethering factor and plays an important role at different steps of vesicular transport. Here we present the 2.2 A-resolution X-ray structure of the globular head region of p115. The structure exhibits an armadillo fold that is decorated by elongated loops and carries a C-terminal non-canonical repeat. This terminal repeat folds into the armadillo superhelical groove and allows homodimeric association with important implications for p115 mediated multiple protein interactions and tethering.

Predictive value of serum Golgi protein 73 for prominent hepatic necroinflammation in chronic HBV infection.

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Xu, Zhengju; Shen, Jiankun; Pan, Xingnan; Wei, Meijuan; Liu, Liguan; Wei, Kaipeng; Liu, Lifei; Yang, Huanwen; Huang, Jinfa

2018-06-01

As a noninvasive marker, serum alanine aminotransferase (ALT) has limitations, because a large proportion of patients chronically infected with hepatitis B virus (HBV) suffer from severe hepatic necroinflammation, but have normal or mildly elevated ALT. In the present study, we aimed to investigate the potential value of serum Golgi protein 73 (GP73) in predicting significant hepatic necroinflamation among chronic HBV infected patients. A cohort of 497 chronic HBV infected patients was retrospectively recruited. Liver biopsy was performed in all patients and serum GP73 levels were measured by enzyme-linked immunosorbent assay. Serum GP73 increased in parallel with the increase in hepatic necroinflammatory activity grade (r = 0.682) and the stage of liver fibrosis (r = 0.539). The positive correlation of serum GP73 with the degree of hepatic necroinflammatory activity was statistically significant, while serum GP73 with the stage of liver fibrosis was weaker than that with hepatic necroinflammation. Furthermore, serum GP73 levels were significantly greater in patients with normal or mildly elevated ALT and significant hepatic necroinflammation (≥G2) than in patients with minimal to mild hepatic necroinflammation. The sensitivity and specificity of GP73 for the diagnosis of G2 hepatic necroinflammation was 42.35% and 95.0%, respectively, at a cut-off value of 88.38 ng/mL. When the cut-off value was set at 124.76 ng/mL, the sensitivity and specificity of GP73 for the diagnosis of G3 hepatic necroinflammation was 55.56% and 97.29%, respectively. These findings indicate that GP73 holds promise as an important candidate for diagnosing significant hepatic necroinflammation. © 2018 Wiley Periodicals, Inc.

Effects of brefeldin A on the endomembrane system and germ tube formation of the tetraspore of Gelidium floridanum (Rhodophyta, Florideophyceae).

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Simioni, Carmen; Rover, Ticiane; Schmidt, Éder C; de L Felix, Marthiellen R; Polo, Luz Karime; Santos, Rodrigo Dos; Costa, Giulia Burle; Kreusch, Marianne; Pereira, Debora T; Ouriques, Luciane C; Bouzon, Zenilda L

2014-06-01

Gelidium floridanum W.R. Taylor tetraspores are units of dispersal and are responsible for substrate attachment. This study aimed to examine evidence of direct interaction between germ tube formation and Golgi activity during tetraspore germination of G. floridanum. After release, the tetraspores were incubated with brefeldin A (BFA) in concentrations of 4 and 8 μM over a 6 h period. The controls and treatments were analyzed with light, fluorescence (FM4-64 dye) and transmission electron microscopy. In the control samples, the Golgi bodies were responsible for germ tube formation. In contrast, BFA-treated samples were observed to inhibit spore adhesion and germ tube formation. These tetraspores also showed an increase in volume (≥30 μm width). BFA treatment also resulted in the disassembly of Golgi cisternae and the formation of vesiculated areas of the cytoplasm, blocking the secretion of protein and amorphous matrix polysaccharides. When stained with FM4-64, the control samples showed fluorescence in the apical region of the germ tube, but the treated samples showed an intense fluorescence throughout the cytoplasm. From these results, we can conclude that the germ tube is formed by the incorporation of vesicles derived from Golgi. Thus, vesicle secretion and Golgi organization are basic processes and essential in adhesion and tube formation. By blocking the secretion of protein and amorphous matrix polysaccharides, BFA treatment precluded tetraspore germination. © 2014 Phycological Society of America.

Whole brain and brain regional coexpression network interactions associated with predisposition to alcohol consumption.

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Lauren A Vanderlinden

Full Text Available To identify brain transcriptional networks that may predispose an animal to consume alcohol, we used weighted gene coexpression network analysis (WGCNA. Candidate coexpression modules are those with an eigengene expression level that correlates significantly with the level of alcohol consumption across a panel of BXD recombinant inbred mouse strains, and that share a genomic region that regulates the module transcript expression levels (mQTL with a genomic region that regulates alcohol consumption (bQTL. To address a controversy regarding utility of gene expression profiles from whole brain, vs specific brain regions, as indicators of the relationship of gene expression to phenotype, we compared candidate coexpression modules from whole brain gene expression data (gathered with Affymetrix 430 v2 arrays in the Colorado laboratories and from gene expression data from 6 brain regions (nucleus accumbens (NA; prefrontal cortex (PFC; ventral tegmental area (VTA; striatum (ST; hippocampus (HP; cerebellum (CB available from GeneNetwork. The candidate modules were used to construct candidate eigengene networks across brain regions, resulting in three "meta-modules", composed of candidate modules from two or more brain regions (NA, PFC, ST, VTA and whole brain. To mitigate the potential influence of chromosomal location of transcripts and cis-eQTLs in linkage disequilibrium, we calculated a semi-partial correlation of the transcripts in the meta-modules with alcohol consumption conditional on the transcripts' cis-eQTLs. The function of transcripts that retained the correlation with the phenotype after correction for the strong genetic influence, implicates processes of protein metabolism in the ER and Golgi as influencing susceptibility to variation in alcohol consumption. Integration of these data with human GWAS provides further information on the function of polymorphisms associated with alcohol-related traits.

Manganese modified CdTe/CdS quantum dots as an immunoassay biosensor for the detection of Golgi protein-73.

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Liu, Wei; Zhang, Aixia; Xu, Guanhong; Wei, Fangdi; Yang, Jing; Hu, Qin

2016-01-05

In this paper, a new fluorescence bioassay for Golgi protein-73 (GP73), a promising marker for monitoring liver tumor, was developed by using anti-GP73 antibody (GP73 Ab) capped quantum dots (QDs) coupled with protein A/G agarose beads in an attempt to improve the analysis time, cost and operation. First, carboxylic-functionalized Mn modified CdTe/CdS QDs were synthesized and covalently conjugated with GP73 Ab, then protein A/G agarose beads were specifically combined with the QDs-conjugated Ab to form the QDs-Ab-beads conjugate, which could capture and separate GP73 from the sample through simple centrifugation. It was found that the fluorescence intensity of the above QDs-Ab-beads biosensor could be specifically quenched by GP73 added. A simple, rapid and specific quantitative method for GP73 protein was proposed using the as-prepared QDs-Ab-beads as a biosensor. Under the optimized conditions, the calibration curve of the proposed assay showed good linearity with a correlation coefficient of 0.9935 in the concentration range of 20-150 ng/mL of GP73 protein. The limit of detection (defined as 3σ/K) was 10 ng/mL. The method built exhibited a great potential in the clinic test of GP73. Copyright © 2015 Elsevier B.V. All rights reserved.

Chimeric forms of furin and TGN38 are transported with the plasma membrane in the trans-Golgi network via distinct endosomal pathways.

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Mallet, W G; Maxfield, F R

1999-07-26

Furin and TGN38 are menbrane proteins that cycle between the plasma membrane and the trans-Golgi network (TGN), each maintaining a predominant distribution in the TGN. We have used chimeric proteins with an extracellular Tac domain and the cytoplasmic domain of TGN38 or furin to study the trafficking of these proteins in endosomes. Previously, we demonstrated that the postendocytic trafficking of Tac-TGN38 to the TGN is via the endocytic recycling pathway (Ghosh, R.N.,W.G. Mallet,T.T. Soe,T.E.McGraw, and F.R. Maxfield.1998.J. Cell Biol.142:923-936). Here we show that internalized Tac-furin is delivered to the TGN through late endosomes, bypassing the endocytic recycling compartment. The transport of Tac-furin from late endosomes to the TGN appears to proceed via an efficient, single-pass mechanism. Delivery of Tac-furin but not Tac-TGN38 to the TGN is blocked by nocodazole, and the two pathways are also differentially affected by wortmannin. These studies demonstrate the existence of two independentpathways for endosomal transport of proteins to the TGN from the plasma membrane.

The nuclear retention signal of HPV16 L2 protein is essential for incoming viral genome to transverse the trans-Golgi network

International Nuclear Information System (INIS)

DiGiuseppe, Stephen; Bienkowska-Haba, Malgorzata; Hilbig, Lydia; Sapp, Martin

2014-01-01

The Human papillomavirus (HPV) capsid is composed of the major and minor capsid proteins, L1 and L2, respectively. Infectious entry requires a complex series of conformational changes in both proteins that lead to uptake and allow uncoating to occur. During entry, the capsid is disassembled and host cyclophilins dissociate L1 protein from the L2/DNA complex. Herein, we describe a mutant HPV16 L2 protein (HPV16 L2-R302/5A) that traffics pseudogenome to the trans-Golgi network (TGN) but fails to egress. Our data provide further evidence that HPV16 traffics through the TGN and demonstrates that L2 is essential for TGN egress. Furthermore, we show that cyclophilin activity is required for the L2/DNA complex to be transported to the TGN which is accompanied by a reduced L1 protein levels. - Highlights: • mNLS mutant HPV16 L2 protein traffics pseudogenome to the TGN but fails to egress. • Cyclophilin activity is required for trafficking of the L2/DNA complex to the TGN. • Majority of L1 protein is shed from the L2/DNA complex prior to reaching the TGN

The nuclear retention signal of HPV16 L2 protein is essential for incoming viral genome to transverse the trans-Golgi network

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DiGiuseppe, Stephen; Bienkowska-Haba, Malgorzata; Hilbig, Lydia; Sapp, Martin, E-mail: msapp1@lsuhsc.edu

2014-06-15

The Human papillomavirus (HPV) capsid is composed of the major and minor capsid proteins, L1 and L2, respectively. Infectious entry requires a complex series of conformational changes in both proteins that lead to uptake and allow uncoating to occur. During entry, the capsid is disassembled and host cyclophilins dissociate L1 protein from the L2/DNA complex. Herein, we describe a mutant HPV16 L2 protein (HPV16 L2-R302/5A) that traffics pseudogenome to the trans-Golgi network (TGN) but fails to egress. Our data provide further evidence that HPV16 traffics through the TGN and demonstrates that L2 is essential for TGN egress. Furthermore, we show that cyclophilin activity is required for the L2/DNA complex to be transported to the TGN which is accompanied by a reduced L1 protein levels. - Highlights: • mNLS mutant HPV16 L2 protein traffics pseudogenome to the TGN but fails to egress. • Cyclophilin activity is required for trafficking of the L2/DNA complex to the TGN. • Majority of L1 protein is shed from the L2/DNA complex prior to reaching the TGN.

Acute ethanol exposure inhibits silencing of cerebellar Golgi cell firing induced by granule cell axon input

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Paolo eBotta

2014-02-01

Full Text Available Golgi cells (GoCs are specialized interneurons that provide inhibitory input to granule cells in the cerebellar cortex. GoCs are pacemaker neurons that spontaneously fire action potentials, triggering spontaneous inhibitory postsynaptic currents in granule cells and also contributing to the generation tonic GABAA receptor-mediated currents in granule cells. In turn, granule cell axons provide feedback glutamatergic input to GoCs. It has been shown that high frequency stimulation of granule cell axons induces a transient pause in GoC firing in a type 2-metabotropic glutamate receptor (mGluR2-dependent manner. Here, we investigated the effect ethanol on the pause of GoC firing induced by high frequency stimulation of granule cell axons. GoC electrophysiological recordings were performed in parasagittal cerebellar vermis slices from postnatal day 23 to 26 rats. Loose-patch cell-attached recordings revealed that ethanol (40 mM reversibly decreases the pause duration. An antagonist of mGluR2 reduced the pause duration but did not affect the effect of ethanol. Whole-cell voltage-clamp recordings showed that currents evoked by an mGluR2 agonist were not significantly affected by ethanol. Perforated-patch experiments in which hyperpolarizing and depolarizing currents were injected into GoCs demonstrated that there is an inverse relationship between spontaneous firing and pause duration. Slight inhibition of the Na+/K+ pump mimicked the effect of ethanol on pause duration. In conclusion, ethanol reduces the granule cell axon-mediated feedback mechanism by reducing the input responsiveness of GoCs. This would result in a transient increase of GABAA receptor-mediated inhibition of granule cells, limiting information flow at the input stage of the cerebellar cortex.

Single-Photon Emission Computerized Tomography (SPECT in Neuropsychiatry: A Review

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B. K. Puri

1992-01-01

Full Text Available Cranial single-photon emission computerized tomography (SPECT or SPET can now give regional cerebral blood flow images with a resolution approaching that of positron emission tomography (PET. In this paper, the use of high resolution SPECT neuroimaging in neuropsychiatric disorders, including Alzheimer's disease, multi-infarct dementia, Pick's disease, progressive supranuclear palsy, Korsakoff's psychosis, Creutzfeld-Jakob disease, Parkinson's disease, Huntington's disease, schizophrenia, mood disorders, obsessive–compulsive disorder, HIV infection and AIDS is reviewed. Finally, further potential research and clinical uses, based on ligand studies, are outlined.

Somal and dendritic development of human CA3 pyramidal neurons from midgestation to middle childhood: a quantitative Golgi study.

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Lu, Dahua; He, Lixin; Xiang, Wei; Ai, Wei-Min; Cao, Ye; Wang, Xiao-Sheng; Pan, Aihua; Luo, Xue-Gang; Li, Zhiyuan; Yan, Xiao-Xin

2013-01-01

The CA3 area serves a key relay on the tri-synaptic loop of the hippocampal formation which supports multiple forms of mnemonic processing, especially spatial learning and memory. To date, morphometric data about human CA3 pyramidal neurons are relatively rare, with little information available for their pre- and postnatal development. Herein, we report a set of developmental trajectory data, including somal growth, dendritic elongation and branching, and spine formation, of human CA3 pyramidal neurons from midgestation stage to middle childhood. Golgi-impregnated CA3 pyramidal neurons in fetuses at 19, 20, 26, 35, and 38 weeks of gestation (GW) and a child at 8 years of age (Y) were analyzed by Neurolucida morphometry. Somal size of the impregnated CA3 cells increased age-dependently among the cases. The length of the apical and basal dendrites of these neurons increased between 26 GW to 38 GW, and appeared to remain stable afterward until 8 Y. Dendritic branching points increased from 26 GW to 38 GW, with that on the apical dendrites slightly reduced at 8 Y. Spine density on the apical and basal dendrites increased progressively from 26 GW to 8 Y. These data suggest that somal growth and dendritic arborization of human CA3 pyramidal neurons occur largely during the second to third trimester. Spine development and likely synaptogenesis on CA3 pyramidal cells progress during the third prenatal trimester and may continue throughout childhood. Copyright © 2012 Wiley Periodicals, Inc.

Endocytosis of wheat germ agglutinin binding sites from the cell surface into a tubular endosomal network.

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Raub, T J; Koroly, M J; Roberts, R M

1990-04-01

By using fluorescence and electron microscopy, the endocytic pathway encountered by cell surface components after they had bound wheat germ agglutinin (WGA) was visualized. The majority of these components are thought to consist of sialylated glycoproteins (HMWAG) that represent a subpopulation of the total cell surface proteins but most of the externally disposed plasma membrane proteins of the cell. Examination of semi-thin sections by medium- and high-voltage electron microscopy revealed the three-dimensional organization of vesicular and tubular endosomes. Binding of either fluorescein isothiocyanate-, horseradish peroxidase-, or ferritin-conjugated WGA to cells at 4 degrees C showed that the HMWAG were distributed uniformly over the cell surface. Warming of surface-labeled cells to 37 degrees C resulted in the endocytosis of WGA into peripheral endosomes via invagination of regions of both coated and uncoated membrane. The peripheral endosome appeared as isolated complexes comprising a vesicular element (300-400 nm diam.) surrounded by and continuous with tubular cisternae (45-60 nm diam.), which did not interconnect the endosomes. After 30 min or more label also became localized in a network of anastomosing tubules (45-60 nm diam.) that were located in the centrosomal region of the cell. Endocytosed WGA-HMWAG complexes did not become associated with cisternae of the Golgi apparatus, although tubular and vesicular endosomes were noted in the vicinity of the trans-Golgi region. The accumulation of WGA-HMWAG in the endosomes within the centrosomal region was inhibited when cells were incubated at 18 degrees C. None of these compartments contained acid phosphatase activity, a result that is consistent with other data that the HMWAG do not pass through lysosomes initially. The kinetics of labeling were consistent with the interpretation that recycling of most of the WGA binding surface glycoproteins occurred rapidly from early peripheral endosomes followed by the

A new member of the GM130 golgin subfamily is expressed in the optic lobe anlagen of the metamorphosing brain of Manduca sexta

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Chiou-Miin Wang

2003-12-01

Full Text Available During metamorphosis of the insect brain, the optic lobe anlagen generate the proliferation centers for the visual cortices. We show here that, in the moth Manduca sexta, an 80 kDa Golgi complex protein (Ms-golgin80 is abundantly expressed in the cytoplasm of neuroblasts and ganglion mother cells in the optic lobe anlagen and proliferation centers. The predicted amino acid sequence for Ms-golgin80 is similar to that of several members of the GM130 subfamily of Golgi-associated proteins, including rat GM130 and human golgin-95. Homologs of Ms-golgin80 from Drosophila melanogaster, Caenorhabditis elegans, and Brugia malayi were identified through homology sequence search. Sequence similarities are present in three regions: the N-terminus, an internal domain of 89 amino acids, and another domain of 89 amino acids near the C-terminus. Structural similarities further suggest that these molecules play the same cellular role as GM130. GM130 is involved in the docking and fusion of coatomer (COP I coated vesicles to the Golgi membranes; it also regulates the fragmentation and subsequent reassembly of the Golgi complex during mitosis. Abundant expression of Ms-golgin80 in neuroblasts and ganglion mother cells and its reduced expression in the neuronal progeny of these cells suggest that this protein may be involved in the maintenance of the proliferative state.

[18F]FDDNP PET in Tauopathies: Correlation to post mortem Pathology in a Case of Progressive Supranuclear Palsy (PSP)

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Villegas, Brendon Josef

This investigation of [18F]FDDNP was conducted in an effort to confirm the presence of disease in a patient with Progressive Supranuclear Palsy (PSP) and to correlate the ante mortem PET scan results to the post mortem pathology. The immunohistochemical and immunofluorescent staining of Paired Helical Filamentous (PHF) tau (AT8) and Amyloid Beta (6F/3D) misfolded proteins demonstrated a widespread deposition in the cortical and subcortical nuclei, the white matter, cerebellar white matter and the medulla oblongata. The in vitro autoradiography demonstrated a neocortical signal comprised of well-delineated amyloid beta in the nucleated layers I/II and hyperphosphorylated tau in the deeper layers III through VI. The autoradiography was well correlated with the immunohistochemical staining in adjacent tissue slides. The binding of the parametric [ 18F]FDDNP distribution volume ratio (DVR) correlated well (Spearman's rho = 0.962, p = .004) with the deposition of tau but not with the presence of amyloid beta (Spearman's rho = -0.829, p = .041). The [ 18F]FDDNP DVR signal appears to be primarily due to the large amount of bound hyperphosphorylated tau (p-tau) and the amyloid beta negligibly contributes to the total signal. Unlabeled FDDNP was shown to bind to tau in the form of globose tangles in the rostral ventromedial medulla as confirmed with both Thioflavin S and PHF-tau Immunofluorescence. The binding of [18F]FDDNP to the human neuroanatomy was investigated in two cohorts of distinct tauopathies and compared to the binding in two tau-negative cohorts against control patients. A cohort of PSP patients (n = 12) with a mean age of 63.8 years and a cohort of Chronic Traumatic Encephalopathy (CTE) patients (n = 14) with a mean age of 58.1 years are both characterized by the presence of various degrees of tau pathology in their brains. The cohort of Parkinson's Disease (PD) patients (n = 16) with a mean age of 63.2 years is initially characterized by clinical symptoms

Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

Energy Technology Data Exchange (ETDEWEB)

Odano, Ikuo [Niigata Univ. (Japan). School of Medicine

1994-04-01

Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) and [sup 99m]Tc-hexamethylpropylene-amine-oxime (HMPAO). The charachteristics, clinical usage and imitation of these two radiolabeled agents are discussed. The advantage of [sup 123]I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of [sup 123]I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of [sup 123]I-IMP. Comparing the rCBF measured by [sup 123]I-IMP with that by [sup 133]Xe inhalation SPECT method, we have to consider PaCO[sub 2] when both SPECT studies are performed, because PaCO[sub 2] is one of the big factors which make effects on the alteration of rCBF. [sup 123]I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume an important datum obtained by the SPECT study with [sup 123]I-IMP, which represent the degree of retention, i.e. binding potential of [sup 123]I-IMP in the brain tissue. I introduced the usage of the distribution volume of [sup 123]I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of [sup 99m] Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence [sup 99m]Tc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author).

Dynamics of synthetic activity of RNA and glycoproteins in epithel cells of endometrium in heifers after ovulation

International Nuclear Information System (INIS)

Pivko, J.; Grafenau, P.; Uhrin, V.; Kopecny, V.

1998-01-01

Synchronized heifers (n=9) of Black Pied HF breed were slaughtered on 3rd, 6th and 9th day of sexual cycle (first day of estrus = 0). Excisions from basal part (A) and functional part (B) of uteri were taken immediately after killing and were processed for autoradiographic analyses. The samples of endometrium were incubated for 20 minutes in isotonic medium with 100 micro Ci uridine (5 -3H) additive with specific activity 740 GBq/mM (UVVVR Prague) to study the RNA synthesis. The endometrium samples were incubated for 60 minutes, and 240 minutes in isotonic medium with 100 micro Ci L-(6-3 H) fucose with specific activity 0.55-1.1 TBqImM (Amersham Int., G.B.) for autoradiographic analysis of the glycoprotein synthesis. The samples were fixed, dehydrated and embedded in Epon 812 after the incubation. The prepared cuts were covered with photographic emulsion and stored in dark box in a refrigerator at 5øC. They were developed in the developer ORWO D 19, stained with methylene blue and examined through the light microscope after one month exposition. We found out by the autoradiographic analysis that the activity of RNA synthesis in cells of the surface epithel is of rising tendency from 3rd to 9th day. The intensity of RNA synthesis does not change in the functional zone during the early lutheal phase, it rises in the basal layer on 6th day, but on 9th day it is the same as on 3rd day. The autoradiographical analysis showed that the activity of RNA synthesis in cells of the surface epithel is of rising tendency from 3rd to 9th day The intensity of RNA synthesis in functional zone does not change during the early lutheal phase, it rises in the basal layer on 6th day, but on 9th day it is the same as on 3rd day. The glycoproteins are synthetised mainly by the Golgi apparatus in supranuclear sphere in the cells of surface epithel and in glandular cells. The glycoproteins were not observed in apical regions of cells on 3rd day of cycle, however, they are intensively

Golgi Analysis of Neuron Morphology in the Presumptive Somatosensory Cortex and Visual Cortex of the Florida Manatee (Trichechus manatus latirostris).

Science.gov (United States)

Reyes, Laura D; Harland, Tessa; Reep, Roger L; Sherwood, Chet C; Jacobs, Bob

2016-01-01

The current study investigates neuron morphology in presumptive primary somatosensory (S1) and primary visual (V1) cortices of the Florida manatee (Trichechus manatus latirostris) as revealed by Golgi impregnation. Sirenians, including manatees, have an aquatic lifestyle, a large body size, and a relatively large lissencephalic brain. The present study examines neuron morphology in 3 cortical areas: in S1, dorsolateral cortex area 1 (DL1) and cluster cortex area 2 (CL2) and in V1, dorsolateral cortex area 4 (DL4). Neurons exhibited a variety of morphological types, with pyramidal neurons being the most common. The large variety of neuron types present in the manatee cortex was comparable to that seen in other eutherian mammals, except for rodents and primates, where pyramid-shaped neurons predominate. A comparison between pyramidal neurons in S1 and V1 indicated relatively greater dendritic branching in S1. Across all 3 areas, the dendritic arborization pattern of pyramidal neurons was also similar to that observed previously in the afrotherian rock hyrax, cetartiodactyls, opossums, and echidnas but did not resemble the widely bifurcated dendrites seen in the large-brained African elephant. Despite adaptations for an aquatic environment, manatees did not share specific neuron types such as tritufted and star-like neurons that have been found in cetaceans. Manatees exhibit an evolutionarily primitive pattern of cortical neuron morphology shared with most other mammals and do not appear to have neuronal specializations for an aquatic niche. © 2016 S. Karger AG, Basel.

Identification of rice cornichon as a possible cargo receptor for the Golgi-localized sodium transporter OsHKT1;3

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Rosas-Santiago, Paul; Lagunas-Gómez, Daniel; Barkla, Bronwyn J.; Vera-Estrella, Rosario; Lalonde, Sylvie; Jones, Alexander; Frommer, Wolf B.; Zimmermannova, Olga; Sychrová, Hana; Pantoja, Omar

2015-01-01

Membrane proteins are synthesized and folded in the endoplasmic reticulum (ER), and continue their path to their site of residence along the secretory pathway. The COPII system has been identified as a key player for selecting and directing the fate of membrane and secretory cargo proteins. Selection of cargo proteins within the COPII vesicles is achieved by cargo receptors. The cornichon cargo receptor belongs to a conserved protein family found in eukaryotes that has been demonstrated to participate in the selection of integral membrane proteins as cargo for their correct targeting. Here it is demonstrated at the cellular level that rice cornichon OsCNIH1 interacts with OsHKT1;3 and, in yeast cells, enables the expression of the sodium transporter to the Golgi apparatus. Physical and functional HKT–cornichon interactions are confirmed by the mating-based split ubiquitin system, bimolecular fluorescence complementation, and Xenopus oocyte and yeast expression systems. The interaction between the two proteins occurs in the ER of plant cells and their co-expression in oocytes leads to the sequestration of the transporter in the ER. In the yeast cornichon mutant erv14, OsHKT1;3 is mistargeted, preventing the toxic effects of sodium transport in the cell observed in wild-type cells or in the erv14 mutant that co-expressed OsHKT1;3 with either OsCNIH1 or Erv14p. Identification and characterization of rice cornichon as a possible cargo receptor opens up the opportunity to improve our knowledge on membrane protein targeting in plant cells. PMID:25750424

Specific magnetic resonance imaging findings in patient with progressive supranuciear palsy

International Nuclear Information System (INIS)

Vuchkova, R.; Zlatareva, D.

2013-01-01

Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disease. The clinical symptoms are vertical supranuclear palsy, gait and postural instability, cognitive deficit, Parkinsonism. It is not always possible to differentiate clinically PSP from other atypical Parkinsonian syndromes and from Parkinson disease. We present a case of 56-years old women with clinically suspected PSP. The typical magnetic resonance findings were of most importance in diagnosis. For diagnosing the disease by means of neuroimaging it is necessary to analyze the sagittal MR images what is achievable in daily routine practice without additional software and post processing. (authors)

Ultrastructural, Antigenic and Physicochemical Characterization of the Mojuí dos Campos (Bunyavirus Isolated from Bat in the Brazilian Amazon Region

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Wanzeller Ana LM

2002-01-01

Full Text Available The Mojuí dos Campos virus (MDCV was isolated from the blood of an unidentified bat (Chiroptera captured in Mojuí dos Campos, Santarém, State of Pará, Brazil, in 1975 and considerated to be antigenically different from other 102 arboviruses belonging to several antigenic groups isolated in the Amazon region or another region by complement fixation tests. The objective of this work was to develop a morphologic, an antigenic and physicochemical characterization of this virus. MDCV produces cytopathic effect in Vero cells, 24 h post-infection (p.i, and the degree of cellular destruction increases after a few hours. Negative staining electron microscopy of the supernatant of Vero cell cultures showed the presence of coated viral particles with a diameter of around 98 nm. Ultrathin sections of Vero cells, and brain and liver of newborn mice infected with MDCV showed an assembly of the viral particles into the Golgi vesicles. The synthesis kinetics of the proteins for MDCV were similar to that observed for other bunyaviruses, and viral proteins could be detected as early as 6 h p.i. Our results reinforce the original studies which had classified MDCV in the family Bunyaviridae, genus Bunyavirus as an ungrouped virus, and it may represent the prototype of a new serogroup.

Yeast Interacting Proteins Database: YHL002W, YNR006W [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available ycling of Golgi proteins and formation of lumenal membranes Rows with this bait as bait (1) Rows with this b...required for recycling Golgi proteins, forming lumenal membranes and sorting ubiquitinated proteins destined...on, as well as for recycling of Golgi proteins and formation of lumenal membranes...ith Hse1p; required for recycling Golgi proteins, forming lumenal membranes and sorting ubiquitinated protei

Yeast Interacting Proteins Database: YNR006W, YHL002W [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available ling Golgi proteins, forming lumenal membranes and sorting ubiquitinated proteins destined for degradation; ..., as well as for recycling of Golgi proteins and formation of lumenal membranes Rows with this prey as prey ...1p; required for recycling Golgi proteins, forming lumenal membranes and sorting ubiquitinated proteins dest...degradation, as well as for recycling of Golgi proteins and formation of lumenal membranes

Identification of rice cornichon as a possible cargo receptor for the Golgi-localized sodium transporter OsHKT1;3.

Science.gov (United States)

Rosas-Santiago, Paul; Lagunas-Gómez, Daniel; Barkla, Bronwyn J; Vera-Estrella, Rosario; Lalonde, Sylvie; Jones, Alexander; Frommer, Wolf B; Zimmermannova, Olga; Sychrová, Hana; Pantoja, Omar

2015-05-01

Membrane proteins are synthesized and folded in the endoplasmic reticulum (ER), and continue their path to their site of residence along the secretory pathway. The COPII system has been identified as a key player for selecting and directing the fate of membrane and secretory cargo proteins. Selection of cargo proteins within the COPII vesicles is achieved by cargo receptors. The cornichon cargo receptor belongs to a conserved protein family found in eukaryotes that has been demonstrated to participate in the selection of integral membrane proteins as cargo for their correct targeting. Here it is demonstrated at the cellular level that rice cornichon OsCNIH1 interacts with OsHKT1;3 and, in yeast cells, enables the expression of the sodium transporter to the Golgi apparatus. Physical and functional HKT-cornichon interactions are confirmed by the mating-based split ubiquitin system, bimolecular fluorescence complementation, and Xenopus oocyte and yeast expression systems. The interaction between the two proteins occurs in the ER of plant cells and their co-expression in oocytes leads to the sequestration of the transporter in the ER. In the yeast cornichon mutant erv14, OsHKT1;3 is mistargeted, preventing the toxic effects of sodium transport in the cell observed in wild-type cells or in the erv14 mutant that co-expressed OsHKT1;3 with either OsCNIH1 or Erv14p. Identification and characterization of rice cornichon as a possible cargo receptor opens up the opportunity to improve our knowledge on membrane protein targeting in plant cells. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Subcellular localization analysis of the closely related Fps/Fes and Fer protein-tyrosine kinases suggests a distinct role for Fps/Fes in vesicular trafficking.

Science.gov (United States)

Zirngibl, R; Schulze, D; Mirski, S E; Cole, S P; Greer, P A

2001-05-15

The subcellular localizations of the Fps/Fes and closely related Fer cytoplasmic tyrosine kinases were studied using green fluorescent protein (GFP) fusions and confocal fluorescence microscopy. In contrast to previous reports, neither kinase localized to the nucleus. Fer was diffusely cytoplasmic throughout the cell cycle. Fps/Fes also displayed a diffuse cytoplasmic localization, but in addition it showed distinct accumulations in cytoplasmic vesicles as well as in a perinuclear region consistent with the Golgi. This localization was very similar to that of TGN38, a known marker of the trans Golgi. The localization of Fps/Fes and TGN38 were both perturbed by brefeldin A, a fungal metabolite that disrupts the Golgi apparatus. Fps/Fes was also found to colocalize to various extents with several Rab proteins, which are members of the monomeric G-protein superfamily involved in vesicular transport between specific subcellular compartments. Using Rabs that are involved in endocytosis (Rab5B and Rab7) or exocytosis (Rab1A and Rab3A), we showed that Fps/Fes is localized in both pathways. These results suggest that Fps/Fes may play a general role in the regulation of vesicular trafficking. Copyright 2001 Academic Press.

Increased expression of Golgi phosphoprotein-3 is associated with tumor aggressiveness and poor prognosis of prostate cancer

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Hua Xing

2012-09-01

Full Text Available Abstract Background To investigate the expression of Golgi phosphoprotein-3 (GOLPH3 in prostate cancer and determine its prognostic value. Methods Immunohistochemical staining for GOLPH3 was performed on tissue microarrays of 342 prostate patients. The correlation between GOLPH3 expression with its clinicopathologic factors was also analyzed in order to determine its prognostic significance. Results GOLPH3 expression of normal prostate tissues, benign prostate hyperplasia, high-grade prostatic intraepithelial neoplasia, and hormone-dependent prostate cancer (HDPC did not show any statistically significant difference. In contrast, statistically significant difference was reported in moderate/intense GOLPH3 expression in cases diagnosed with HDPC and castration resistant prostate cancer (CRPC (P P = 0.012, higher Gleason score (P = 0.017, bone metastasis (P = 0.024, higher baseline prostate-specific antigen (PSA (P = 0.038, and higher PSA nadir (P = 0.032. A significantly negative correlation was found between moderate/intense GOLPH3 expression and disease-free survival (DFS (HR = 0.28, P = 0.012 and overall survival (OS (HR = 0.42, P = 0.027. Univariated analysis indicated that moderate/intense GOLPH3 expression created a significantly prognostic impact in patients with CRPC. On the other hand, multivariate analysis indicated that GOLPH3 was a significantly independent prognostic factor of DFS (P = 0.027 in all prostate cancer patients. Conclusions In this study, it was discovered that the overexpression of GOLPH3 is associated with the transition of prostate cancer from hormone sensitive phase to hormone refractory phase. GOLPH3 might be an important prognostic factor of DFS and OS in patients with prostate cancer. In totality, GOLPH3 could be used as a novel candidate in devising a more effective therapeutic strategy to tackle CRPC. Virtual slides The virtual slide(s for this article can be found here

I-Love-Q to the extreme

Science.gov (United States)

Silva, Hector O.; Yunes, Nicolás

2018-01-01

Certain bulk properties of neutron stars, in particular their moment of inertia, rotational quadrupole moment and tidal Love number, when properly normalized, are related to one another in a nearly equation of state independent way. The goal of this paper is to test these relations with extreme equations of state at supranuclear densities constrained to satisfy only a handful of generic, physically sensible conditions. By requiring that the equation of state be (i) barotropic and (ii) its associated speed of sound be real, we construct a piecewise function that matches a tabulated equation of state at low densities, while matching a stiff equation of state parametrized by its sound speed in the high-density region. We show that the I-Love-Q relations hold to 1 percent with this class of equations of state, even in the extreme case where the speed of sound becomes superluminal and independently of the transition density. We also find further support for the interpretation of the I-Love-Q relations as an emergent symmetry due to the nearly constant eccentricity of isodensity contours inside the star. These results reinforce the robustness of the I-Love-Q relations against our current incomplete picture of physics at supranuclear densities, while strengthening our confidence in the applicability of these relations in neutron star astrophysics.

Biomarkers in Neural Disorders

Science.gov (United States)

2017-09-07

Parkinson's Disease; Alzheimer's Disease; Progressive Supranuclear Palsy; Essential Tremor; Multiple System Atrophy; Drug Induced Parkinson's Disease; Diffuse Lewy Body Disease; Myasthenia Gravis; Spinal Cord Injuries

Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

Energy Technology Data Exchange (ETDEWEB)

Odano, Ikuo (Niigata Univ. (Japan). School of Medicine)

1994-04-01

Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) and [sup 99m]Tc-hexamethylpropylene-amine-oxime (HMPAO). The charachteristics, clinical usage and imitation of these two radiolabeled agents are discussed. The advantage of [sup 123]I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of [sup 123]I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of [sup 123]I-IMP. Comparing the rCBF measured by [sup 123]I-IMP with that by [sup 133]Xe inhalation SPECT method, we have to consider PaCO[sub 2] when both SPECT studies are performed, because PaCO[sub 2] is one of the big factors which make effects on the alteration of rCBF. [sup 123]I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume an important datum obtained by the SPECT study with [sup 123]I-IMP, which represent the degree of retention, i.e. binding potential of [sup 123]I-IMP in the brain tissue. I introduced the usage of the distribution volume of [sup 123]I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of [sup 99m] Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence [sup 99m]Tc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author).

Effect of colchicine on the transport of precursor enamel protein in secretory ameloblasts studied by 3H-proline radioautography in vitro

International Nuclear Information System (INIS)

Matsuo, S.; Takano, Y.; Wakisaka, S.; Ichikawa, H.; Nishikawa, S.; Akai, M.

1988-01-01

The incorporation of 3H-proline into the secretory ameloblasts of rat molar tooth germs cultured with or without colchicine was studied by light and electron microscope radioautography to determine the function of microtubules in the transport of precursor enamel protein from the rough-surfaced endoplasmic reticulum (rER) to the Golgi cisternae. The grain counts over the transitional vesicles, which accumulated in various cellular regions with colchicine treatment, continued to increase with chase time, unlike in controls. At 30 and 90 min chase, these counts were significantly higher than in controls. Moreover, the total grain count over the organelles (rER, pale granules, and transitional vesicles), which are positioned before the Golgi cisternae in the synthetic pathway, maintained a significantly higher level at 90 min chase in colchicine-treated tooth germs than in controls. The transport of synthesized protein to the Golgi cisternae via transitional vesicles was suppressed in colchicine-treated tooth germs. Some grains appeared with time over pale granular materials that appeared in the intercellular spaces of secretory ameloblasts with colchicine treatment. However, at each chase period, the grain count over pale granular materials was not so high as the count over the enamel in control. The present results indicate that colchicine affects the transport of newly synthesized protein from the rER to the Golgi cisterna via transitional vesicles, probably by interfering with the oriented transport related to microtubular function. It is suggested that the microtubular system may be concerned with the movement of the transitional vesicles

The impossible interview with the man of the hidden biological structures. Interview by Paolo Mazzarello.

Science.gov (United States)

Golgi, Camillo

2006-12-01

This paper presents an "impossible interview" to Professor Camillo Golgi, placed in time in December 1906. The Italian Professor Golgi from Pavia has been awarded the Nobel Prize for Physiology or Medicine ex aequo with the Spanish anatomist Santiago Ramón y Cajal. Both scientists have obtained the award for their work on the anatomy of the nervous system. However, they have opposite views on the mechanisms underlying nervous functions. Golgi believes that the axons stained by his "black reaction" form a continuous anatomical or functional network along which nervous impulses propagate. Ramón y Cajal is the paladin of the neuron theory, a hypothesis questioned by Golgi in his Nobel lecture of Tuesday, December 11. After the ceremony, an independent journalist has interviewed Professor Golgi in the Grand Hotel in Stockholm. Excerpts about his education, his main scientific discoveries, and his personal life are here given (reconstructing the "impossible interview" on the basis of Golgi's original writings).

The Swedish BioFINDER 2 Study

Science.gov (United States)

2018-04-16

Dementia; Alzheimer Disease; Parkinson Disease; Lewy Body Disease; Parkinson-Dementia Syndrome; Frontotemporal Degeneration; Semantic Dementia; Progressive Nonfluent Aphasia; Progressive Supranuclear Palsy; Corticobasal Degeneration; Multiple System Atrophy; Mild Cognitive Impairment

Symmetrical corticobasal syndrome caused by a novel c.314dup progranulin mutation

NARCIS (Netherlands)

E.G.P. Dopper (Elise); H. Seelaar (Harro); W.Z. Chiu (Wang Zheng); I. de Koning (Inge); R. van Minkelen (Rick); M.C. Baker (Matthew); A.J.M. Rozemuller (Annemieke); R. Rademakers (Rosa); J.C. van Swieten (John)

2011-01-01

textabstractCorticobasal syndrome (CBS) is characterised by asymmetrical parkinsonism and cognitive impairment. The underlying pathology varies between corticobasal degeneration, progressive supranuclear palsy, Alzheimer's disease, Creutzfeldt-Jakob disease and frontotemporal lobar degeneration

Human Ubc9 is involved in intracellular HIV-1 Env stability after trafficking out of the trans-Golgi network in a Gag dependent manner.

Directory of Open Access Journals (Sweden)

Christopher R Bohl

Full Text Available The cellular E2 Sumo conjugase, Ubc9 interacts with HIV-1 Gag, and is important for the assembly of infectious HIV-1 virions. In the previous study we demonstrated that in the absence of Ubc9, a defect in virion assembly was associated with decreased levels of mature intracellular Envelope (Env that affected Env incorporation into virions and virion infectivity. We have further characterized the effect of Ubc9 knockdown on HIV Env processing and assembly. We found that gp160 stability in the endoplasmic reticulum (ER and its trafficking to the trans-Golgi network (TGN were unaffected, indicating that the decreased intracellular mature Env levels in Ubc9-depleted cells were due to a selective degradation of mature Env gp120 after cleavage from gp160 and trafficked out of the TGN. Decreased levels of Gag and mature Env were found to be associated with the plasma membrane and lipid rafts, which suggest that these viral proteins were not trafficked correctly to the assembly site. Intracellular gp120 were partially rescued when treated with a combination of lysosome inhibitors. Taken together our results suggest that in the absence of Ubc9, gp120 is preferentially degraded in the lysosomes likely before trafficking to assembly sites leading to the production of defective virions. This study provides further insight in the processing and packaging of the HIV-1 gp120 into mature HIV-1 virions.

Symmetrical Corticobasal Syndrome Caused by a Novel c.314dup Progranulin Mutation

NARCIS (Netherlands)

Dopper, E.G.; Seelaar, H.; Chiu, W.Z.; de Koning, I.; van Minkelen, R.; Baker, M.C.; Rozemuller, A.J.; Rademakers, R.; van Swieten, J.C.

2011-01-01

Corticobasal syndrome (CBS) is characterised by asymmetrical parkinsonism and cognitive impairment. The underlying pathology varies between corticobasal degeneration, progressive supranuclear palsy, Alzheimer's disease, Creutzfeldt-Jakob disease and frontotemporal lobar degeneration sometimes in

Golgi analysis of tangential neurons in the lobula plate of Drosophila ...

Indian Academy of Sciences (India)

Unknown

possibly due to the shape of the compound eye of Drosophila which is reduced in the fronto-dorsal region as ...... properties of the vertical cells in the third optic ganglion of ... Egelhaaf M 1985 On the neuronal basis of figure-ground dis-.

Sphingomyelin synthases regulate protein trafficking and secretion.

Directory of Open Access Journals (Sweden)

Marimuthu Subathra

Full Text Available Sphingomyelin synthases (SMS1 and 2 represent a class of enzymes that transfer a phosphocholine moiety from phosphatidylcholine onto ceramide thus producing sphingomyelin and diacylglycerol (DAG. SMS1 localizes at the Golgi while SMS2 localizes both at the Golgi and the plasma membrane. Previous studies from our laboratory showed that modulation of SMS1 and, to a lesser extent, of SMS2 affected the formation of DAG at the Golgi apparatus. As a consequence, down-regulation of SMS1 and SMS2 reduced the localization of the DAG-binding protein, protein kinase D (PKD, to the Golgi. Since PKD recruitment to the Golgi has been implicated in cellular secretion through the trans golgi network (TGN, the effect of down-regulation of SMSs on TGN-to-plasma membrane trafficking was studied. Down regulation of either SMS1 or SMS2 significantly retarded trafficking of the reporter protein vesicular stomatitis virus G protein tagged with GFP (VSVG-GFP from the TGN to the cell surface. Inhibition of SMSs also induced tubular protrusions from the trans Golgi network reminiscent of inhibited TGN membrane fission. Since a recent study demonstrated the requirement of PKD activity for insulin secretion in beta cells, we tested the function of SMS in this model. Inhibition of SMS significantly reduced insulin secretion in rat INS-1 cells. Taken together these results provide the first direct evidence that both enzymes (SMS1 and 2 are capable of regulating TGN-mediated protein trafficking and secretion, functions that are compatible with PKD being a down-stream target for SMSs in the Golgi.

Role of N-terminal 28-amino-acid region of Rhizopus oryzae lipase in directing proteins to secretory pathway of Aspergillus oryzae.

Science.gov (United States)

Hama, Shinji; Tamalampudi, Sriappareddy; Shindo, Naoki; Numata, Takao; Yamaji, Hideki; Fukuda, Hideki; Kondo, Akihiko

2008-07-01

To develop a new approach for improving heterologous protein production in Aspergillus oryzae, we focused on the functional role of the N-terminal region of Rhizopus oryzae lipase (ROL). Several N-terminal deletion variants of ROL were expressed in A. oryzae. Interestingly, a segment of 28 amino acids from the C-terminal region of the propeptide (N28) was found to be critical for secretion of ROL into the culture medium. To further investigate the role of N28, the ROL secretory process was visualized in vivo using ROL-green fluorescent protein (GFP) fusion proteins. In cells producing ROL with N28, fluorescence observations showed that the fusion proteins are transported through endoplasmic reticulum (ER), Golgi, and cell wall, which is one of the typical secretory processes in a eukaryotic cell. Because the expression of the mature ROL-GFP fusion protein induced fluorescence accumulation without its translocation into the ER, N28 is considered to play a crucial role in protein transport. When N28 was inserted between the secretion signal and GFP, fluorescence observations showed that GFP, which is originally a cytoplasmic protein, was efficiently translocated into the ER of A. oryzae, resulting in an enhanced secretion of mature GFP after proteolytic cleavage of N28. These findings suggest that N28 facilitates protein translocation into ER and can be a promising candidate for improving heterologous protein production in A. oryzae.

Probing Conformational Dynamics of Tau Protein by Hydrogen/Deuterium Exchange Mass Spectrometry

Science.gov (United States)

Huang, Richard Y.-C.; Iacob, Roxana E.; Sankaranarayanan, Sethu; Yang, Ling; Ahlijanian, Michael; Tao, Li; Tymiak, Adrienne A.; Chen, Guodong

2018-01-01

Fibrillization of the microtubule-associated protein tau has been recognized as one of the signature pathologies of the nervous system in Alzheimer's disease, progressive supranuclear palsy, and other tauopathies. The conformational transition of tau in the fibrillization process, tau monomer to soluble aggregates to fibrils in particular, remains unclear. Here we report on the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) in combination with other biochemical approaches, including Thioflavin S fluorescence measurements, enzyme-linked immunosorbent assay (ELISA), and Western blotting to understand the heparin-induced tau's fibrillization. HDX-MS studies including anti-tau antibody epitope mapping experiments provided molecular level details of the full-length tau's conformational dynamics and its regional solvent accessibility upon soluble aggregates formation. The results demonstrate that R3 region in the full-length tau's microtubule binding repeat region (MTBR) is stabilized in the aggregation process, leaving both N and C terminal regions to be solvent exposed in the soluble aggregates and fibrils. The findings also illustrate the practical utility of orthogonal analytical methodologies for the characterization of protein higher order structure. [Figure not available: see fulltext.

Iron as a risk factor in neurological diseases

Science.gov (United States)

Galazka-Friedman, Jolanta

2008-02-01

In this review the properties of iron in various human brain structures (e.g. Substantia nigra, globus pallidus, hippocampus) were analyzed to assess the possibility of initiation of oxidative stress leading to such diseases as Parkinson’s and Alzheimer’s disease, and progressive supranuclear palsy. Our own studies with the use of Mössbauer spectroscopy, electron microscopy and enzyme-linked immuno-absorbent assay (ELISA) were confronted with other methods used in other laboratories. Our results suggest that hippocampus is the most fragile for oxidative stress structure in human brain (the death of nervous cells in hippocampus leads to Alzheimer’s disease). Changes in iron metabolism were also found in substantia nigra (the death of nervous cells of this structure produces Parkinson’s disease) and in globus pallidus (neurodegeneration of this structure causes progressive supranuclear palsy).

Iron as a risk factor in neurological diseases

International Nuclear Information System (INIS)

Galazka-Friedman, Jolanta

2008-01-01

In this review the properties of iron in various human brain structures (e.g. Substantia nigra, globus pallidus, hippocampus) were analyzed to assess the possibility of initiation of oxidative stress leading to such diseases as Parkinson's and Alzheimer's disease, and progressive supranuclear palsy. Our own studies with the use of Moessbauer spectroscopy, electron microscopy and enzyme-linked immuno-absorbent assay (ELISA) were confronted with other methods used in other laboratories. Our results suggest that hippocampus is the most fragile for oxidative stress structure in human brain (the death of nervous cells in hippocampus leads to Alzheimer's disease). Changes in iron metabolism were also found in substantia nigra (the death of nervous cells of this structure produces Parkinson's disease) and in globus pallidus (neurodegeneration of this structure causes progressive supranuclear palsy).

GRASP: A multitasking tether

Directory of Open Access Journals (Sweden)

Catherine eRabouille

2016-01-01

Full Text Available Originally identified as Golgi stacking factors in vitro, the Golgi reassembly stacking protein (GRASP family has been shown to act as membrane tethers with multiple cellular roles. As an update to previous comprehensive reviews of the GRASP family (Vinke et al., 2011 (Giuliani et al., 2011;Jarvela and Linstedt, 2012, we outline here the latest findings concerning their diverse roles. New insights into the mechanics of GRASP-mediated tethering come from recent crystal structures. The models of how GRASP65 and GRASP55 tether membranes relate directly to their role in Golgi ribbon formation in mammalian cells and the unlinking of the ribbon at the onset of mitosis. However, it is also clear that GRASPs act outside the Golgi with roles at the ER and ER exit sites (ERES. Furthermore, the proteins of this family display other roles upon cellular stress, especially in mediating unconventional secretion of both transmembrane proteins (Golgi bypass and cytoplasmic proteins (through secretory autophagosomes.

Progressive Supranuclear Palsy Misdiagnosed as Parkinson's ...

African Journals Online (AJOL)

cerebellar peduncle were 0.30 cm2 and 0.28 cm on the right and left sides, respectively [Figure 2], and the pons to mid‑brain ratio was 5.71 [Figure 3]. ..... Longoni G, Agosta F, Kostić VS, Stojković T, Pagani E,. Stošić‑Opinćal T, et al.

Entry of Shiga toxin into cells

DEFF Research Database (Denmark)

Sandvig, Kirsten; van Deurs, Bo

1994-01-01

Cellebiologi, Shiga toxin, receptors, glycolipids, endocytosis, trans-Golgi network, endoplasmic reticulum, retrograde transport......Cellebiologi, Shiga toxin, receptors, glycolipids, endocytosis, trans-Golgi network, endoplasmic reticulum, retrograde transport...

Development of an alpha-fetoprotein and Golgi protein 73 multiplex detection assay using xMAP technology.

Science.gov (United States)

Wu, Yun; Ma, Jie; Wang, Yipeng; Zhang, Yonghong; Hou, Yongjin; Zhang, Chunming; Sun, Huanqin; Sun, Jianping; Wang, Zikang; Li, Ning

2018-04-06

Development of a new method to simultaneously detect Alpha-fetoprotein (AFP) and Golgi protein 73 (GP73) from peripheral blood. Anti human AFP and GP73 monoclonal antibodies was used to develop a sandwich immunity reaction using xMAP technology for the simultaneous detection of plasma AFP and GP73. The assay evaluated the sensitivity, cross reactivity, range of detection, precision, recovery and linearity dilution effect. The assay utilized plasma samples and compared its performance with commercially available Enzyme Linked Immunosorbent Assay (ELISA) kits. The assay was successful in detecting AFP and GP73 simultaneously. Validation experiments demonstrated the limit of detection was AFP 0.006 μg/l and GP73 0.482 μg/l. The functional sensitivity was AFP 0.010 μg/l and GP73 0.640 μg/l. The range of detection was AFP 0.01-50 μg/l and GP73 0.64-100 μg/l. No cross reactivity was observed. The intra- and inter-assay variation for AFP was 0.19-3.46% and 3.1-5.8% and for GP73 was 1.5-3.2% and 1.1-7.6% respectively. The recovery for AFP was 96-106% and GP73 was 89-110%. 80 clinical plasma samples from healthy controls, and patients with liver cirrhosis and Hepatocellular Carcinoma (HCC) were evaluated. For healthy controls (n = 25), the AFP was 2.40 (1.55, 3.30) μg/l and GP73 was 42.60 (39.10, 57.40) μg/l. For patients with liver cirrhosis (n = 19), the AFP was 2.60 (1.70, 4.20) μg/l and GP73 was 136.10 (92.10, 261.70) μg/l, and for HCC patients (n = 36), the AFP was 13.65 (3.35, 158.88) μg/l and GP73 was 186.25 (96.73, 262.03) μg/l. The new assay demonstrated a good correlation with commercially available ELISA kits (correlation coefficients (r) were 0.997 (AFP, p < 0.001) and 0.959 (GP73, p < 0.001). The method demonstrated a sensitive, effective and accurate method for the simultaneous detection of AFP and GP73, and could be used clinically for routine detection and monitoring of patients with chronic hepatitis B

Mutations in the C-terminal region affect subcellular localization of crucian carp herpesvirus (CaHV) GPCR.

Science.gov (United States)

Wang, Jun; Gui, Lang; Chen, Zong-Yan; Zhang, Qi-Ya

2016-08-01

G protein-coupled receptors (GPCRs) are known as seven transmembrane domain receptors and consequently can mediate diverse biological functions via regulation of their subcellular localization. Crucian carp herpesvirus (CaHV) was recently isolated from infected fish with acute gill hemorrhage. CaHV GPCR of 349 amino acids (aa) was identified based on amino acid identity. A series of variants with truncation/deletion/substitution mutation in the C-terminal (aa 315-349) were constructed and expressed in fathead minnow (FHM) cells. The roles of three key C-terminal regions in subcellular localization of CaHV GPCR were determined. Lysine-315 (K-315) directed the aggregation of the protein preferentially at the nuclear side. Predicted N-myristoylation site (GGGWTR, aa 335-340) was responsible for punctate distribution in periplasm or throughout the cytoplasm. Predicted phosphorylation site (SSR, aa 327-329) and GGGWTR together determined the punctate distribution in cytoplasm. Detection of organelles localization by specific markers showed that the protein retaining K-315 colocalized with the Golgi apparatus. These experiments provided first evidence that different mutations of CaHV GPCR C-terminals have different affects on the subcellular localization of fish herpesvirus-encoded GPCRs. The study provided valuable information and new insights into the precise interactions between herpesvirus and fish cells, and could also provide useful targets for antiviral agents in aquaculture.

Cellular Protein WDR11 Interacts with Specific Herpes Simplex Virus Proteins at the trans-Golgi Network To Promote Virus Replication

Science.gov (United States)

Taylor, Kathryne E.

2015-01-01

ABSTRACT It has recently been proposed that the herpes simplex virus (HSV) protein ICP0 has cytoplasmic roles in blocking antiviral signaling and in promoting viral replication in addition to its well-known proteasome-dependent functions in the nucleus. However, the mechanisms through which it produces these effects remain unclear. While investigating this further, we identified a novel cytoplasmic interaction between ICP0 and the poorly characterized cellular protein WDR11. During an HSV infection, WDR11 undergoes a dramatic change in localization at late times in the viral replication cycle, moving from defined perinuclear structures to a dispersed cytoplasmic distribution. While this relocation was not observed during infection with viruses other than HSV-1 and correlated with efficient HSV-1 replication, the redistribution was found to occur independently of ICP0 expression, instead requiring viral late gene expression. We demonstrate for the first time that WDR11 is localized to the trans-Golgi network (TGN), where it interacts specifically with some, but not all, HSV virion components, in addition to ICP0. Knockdown of WDR11 in cultured human cells resulted in a modest but consistent decrease in yields of both wild-type and ICP0-null viruses, in the supernatant and cell-associated fractions, without affecting viral gene expression. Although further study is required, we propose that WDR11 participates in viral assembly and/or secondary envelopment. IMPORTANCE While the TGN has been proposed to be the major site of HSV-1 secondary envelopment, this process is incompletely understood, and in particular, the role of cellular TGN components in this pathway is unknown. Additionally, little is known about the cellular functions of WDR11, although the disruption of this protein has been implicated in multiple human diseases. Therefore, our finding that WDR11 is a TGN-resident protein that interacts with specific viral proteins to enhance viral yields improves both

18F-FDG PET in Parkinsonism: Differential Diagnosis and Evaluation of Cognitive Impairment.

Science.gov (United States)

Meyer, Philipp T; Frings, Lars; Rücker, Gerta; Hellwig, Sabine

2017-12-01

Accurate differential diagnosis of parkinsonism is of paramount therapeutic and prognostic importance. In addition, with the development of invasive therapies and novel disease-specific therapies, strategies for patient enrichment in trial populations are of growing importance. Imaging disease-specific patterns of regional glucose metabolism with PET and 18 F-FDG allows for a highly accurate distinction between Parkinson disease (PD) and atypical parkinsonian syndromes, including multiple-system atrophy, progressive supranuclear palsy, and corticobasal degeneration. On the basis of a preliminary metaanalysis of currently available studies with inclusion of multiple disease groups, we estimated that the diagnostic sensitivity and specificity for visual PET readings supported by voxel-based statistical analyses for diagnosis of atypical parkinsonian syndromes are 91.4% and 90.6%, respectively. The diagnostic specificity of 18 F-FDG PET for diagnosing multiple-system atrophy, progressive supranuclear palsy, and corticobasal degeneration was consistently shown to be high (>90%), whereas sensitivity was more variable (>75%). It is increasingly acknowledged that cognitive impairment represents a major challenge in PD, with mild cognitive impairment being a prodromal stage of PD with dementia (PDD). In line with clinical and neuropsychologic studies, recent PET studies demonstrated that posterior cortical dysfunction in nondemented PD patients precedes cognitive decline and the development of PDD by several years. Taken together, the current literature underscores the utility of 18 F-FDG PET for diagnostic evaluation of parkinsonism and the promising role of 18 F-FDG PET for assessment and risk stratification of cognitive impairment in PD. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Yeast Interacting Proteins Database: YGL145W, YNL258C [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available ripheral membrane protein required for Golgi-to-ER retrograde traffic; component ... membrane protein required for Golgi-to-ER retrograde traffic; component of the ER target site that interact

GOLGA2 loss causes fibrosis with autophagy in the mouse lung and liver.

Science.gov (United States)

Park, Sungjin; Kim, Sanghwa; Kim, Min Jung; Hong, Youngeun; Lee, Ah Young; Lee, Hyunji; Tran, Quangdon; Kim, Minhee; Cho, Hyeonjeong; Park, Jisoo; Kim, Kwang Pyo; Park, Jongsun; Cho, Myung-Haing

2018-01-01

Autophagy is a biological recycling process via the self-digestion of organelles, proteins, and lipids for energy-consuming differentiation and homeostasis. The Golgi serves as a donor of the double-membraned phagophore for autophagosome assembly. In addition, recent studies have demonstrated that pulmonary and hepatic fibrosis is accompanied by autophagy. However, the relationships among Golgi function, autophagy, and fibrosis are unclear. Here, we show that the deletion of GOLGA2, encoding a cis-Golgi protein, induces autophagy with Golgi disruption. The induction of autophagy leads to fibrosis along with the reduction of subcellular lipid storage (lipid droplets and lamellar bodies) by autophagy in the lung and liver. GOLGA2 knockout mice clearly demonstrated fibrosis features such as autophagy-activated cells, densely packed hepatocytes, increase of alveolar macrophages, and decrease of alveolar surfactant lipids (dipalmitoylphosphatidylcholine). Therefore, we confirmed the associations among Golgi function, fibrosis, and autophagy. Moreover, GOLGA2 knockout mice may be a potentially valuable animal model for studying autophagy-induced fibrosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Imaging of the dopaminergic neurotransmission system using single-photon emission tomography and positron emission tomography in patients with parkinsonism

NARCIS (Netherlands)

Booij, J.; Tissingh, G.; Winogrodzka, A.; van Royen, E. A.

1999-01-01

Parkinsonism is a feature of a number of neurodegenerative diseases, including Parkinson's disease, multiple system atrophy and progressive supranuclear palsy. The results of post-mortem studies point to dysfunction of the dopaminergic neurotransmitter system in patients with parkinsonism. Nowadays,

Coronavirus envelope (E) protein remains at the site of assembly

International Nuclear Information System (INIS)

Venkatagopalan, Pavithra; Daskalova, Sasha M.; Lopez, Lisa A.; Dolezal, Kelly A.; Hogue, Brenda G.

2015-01-01

Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes

The golgin GMAP-210 is required for efficient membrane trafficking in the early secretory pathway.

Science.gov (United States)

Roboti, Peristera; Sato, Keisuke; Lowe, Martin

2015-04-15

Golgins are coiled-coil proteins that participate in membrane-tethering events at the Golgi complex. Golgin-mediated tethering is thought to be important for vesicular trafficking and Golgi organization. However, the degree to which individual golgins contribute to these processes is poorly defined, and it has been proposed that golgins act in a largely redundant manner. Previous studies on the golgin GMAP-210 (also known as TRIP11), which is mutated in the rare skeletal disorder achondrogenesis type 1A, have yielded conflicting results regarding its involvement in trafficking. Here, we re-investigated the trafficking role of GMAP-210, and found that it is indeed required for efficient trafficking in the secretory pathway. GMAP-210 acts at both the endoplasmic reticulum (ER)-to-Golgi intermediate compartment (ERGIC) and Golgi complex during anterograde trafficking, and is also required for retrograde trafficking to the ER. Using co-depletion experiments, we also found that GMAP-210 acts in a partially redundant manner with the golgin GM130 to ensure efficient anterograde cargo delivery to the cis-Golgi. In summary, our results indicate a role for GMAP-210 in several trafficking steps at the ER-Golgi interface, some of which are partially redundant with another golgin, namely GM130 (also known as GOLGA2). © 2015. Published by The Company of Biologists Ltd.

Coronavirus envelope (E) protein remains at the site of assembly

Energy Technology Data Exchange (ETDEWEB)

Venkatagopalan, Pavithra [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Daskalova, Sasha M. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); Department of Biochemistry and Chemistry, Arizona State University, Tempe, AZ 85287-5401 (United States); Lopez, Lisa A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Molecular and Cellular Biology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Dolezal, Kelly A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Hogue, Brenda G., E-mail: Brenda.Hogue@asu.edu [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States)

2015-04-15

Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes.

Analytic study of regional changes in carcinoma of the cervix uteri following linac irradiation, 3

International Nuclear Information System (INIS)

Yamashita, Michitaka

1977-01-01

To observe regional changes following Linac irradiation therapy for 15 patients with carcinoma of the cervix uteri, an electron microscopic study of the carcinomatous cells of a parabasal type was made, and the following conclusion was obtained. Early changes which were seen following 1000 R irradiation were an appearance of various lysosomes and a remarkable appearance of the Golgi's apparatus. Some other changes were noted in mitochondria, vesicles, and free ribosomes, while very slight changes in the nuclei. After 2000 R irradiation, the foregoing early changes and a tendency of cells separated became more distinctive. Following an irradiation of 3000 R, changes were noted in the nuclei, destruction of the nuclear membrane and agglutination of chromatin being prominent. Glycogen granules were also noted. After an irradiation of 4000-5000 R, the carcinomatous cells were necrotized and ill-defined. There were remarkable destructions of the nuclei and intracellular organellas. On the basis of the foregoing findings, it is considered that the effect of irradiation on the carcinomatous cells of a parabasal type in carcinoma of the cervix uteri appears as a change in the cytoplasm which is followed by the destructive change of the nuclei. A difference in the effect of irradiation was conspicuous in the changes of the lysosome. In remarkably effective cases, there occurred an early appearance and an early inactivation of the lysosome. However, in ineffective cases, those changes appeared after receiving 1000 R more irradiation. (Ueda, J.)

Genetics Home Reference: COG5-congenital disorder of glycosylation

Science.gov (United States)

... of proteins known as the conserved oligomeric Golgi (COG) complex. This complex functions in the Golgi apparatus , ... can perform a wider variety of functions. The COG complex takes part in the transport of proteins, ...

Assessment of serum Golgi protein 73 as a biomarker for the diagnosis of significant fibrosis in patients with chronic HBV infection.

Science.gov (United States)

Cao, Z; Li, Z; Wang, Y; Liu, Y; Mo, R; Ren, P; Chen, L; Lu, J; Li, H; Zhuang, Y; Liu, Y; Wang, X; Zhao, G; Tang, W; Xiang, X; Wang, H; Cai, W; Liu, L; Zhu, C; Bao, S; Xie, Q

2017-11-01

Transient elastography (TE) is accurate in staging fibrosis noninvasively. However, a reliable serum biomarker with comparable accuracy is also important, especially when TE is unreliable/unavailable. Therefore, we aimed to evaluate the diagnostic performance of serum Golgi protein 73 (GP73) for significant fibrosis in patients with chronic HBV infection. A total of 801 patients with chronic liver disease (CLD; 492 chronic HBV infection and 309 non-HBV liver disease) with liver biopsy performance were enrolled. Healthy controls (n = 180) and hepatocellular carcinoma (HCC) patients (n = 85) were included for comparisons. Liver biopsy was used as the reference method for fibrosis staging. Serum GP73 level was measured in duplicate in double-blind fashion. Serum GP73 was highest in HCC but also significantly higher in chronic hepatitis B than in healthy controls. The elevation of serum GP73 in non-HCC patients was significantly associated with the presence of significant fibrosis independently of ALT level, liver stiffness (LS) value, inflammation grade and other confounding factors. The diagnostic performance of serum GP73 was accurate in antiviral-naïve HBV patients (area under the receiver operating curve [AUROC], 0.76 95% CI: 0.72-0.81) but not in patients with ongoing antiviral treatment (AUROC, 0.60). The utility of serum GP73 was also confirmed in non-HBV CLD (AUROC, 0.80 95% CI: 0.75-0.85). Serum GP73 was comparable to LS (AUROC, 0.78 95% CI: 0.73-0.82) and significantly better than AST to platelet ratio index (APRI) (AUROC, 0.67 95% CI: 0.62-0.72) and FIB-4 (AUROC, 0.68 95% CI: 0.63-0.73). In conclusion, serum GP73 is an accurate serum marker for significant fibrosis in chronic HBV infection, with higher accuracy than APRI and FIB-4. Serum GP73 is potentially a complementary tool for TE when evaluating the necessity of antiviral treatment, particularly in patients without definite antiviral indication. © 2017 John Wiley & Sons Ltd.

Yeast Interacting Proteins Database: YNL258C, YGL145W [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available YNL258C DSL1 Peripheral membrane protein required for Golgi-to-ER retrograde traffi...t description Peripheral membrane protein required for Golgi-to-ER retrograde traffic; component of the ER t

Vascular incontinence: incontinence in the elderly due to ischemic white matter changes

Directory of Open Access Journals (Sweden)

Ryuji Sakakibara

2012-09-01

Full Text Available This review article introduces the new concept of vascular incontinence, a disorder of bladder control resulting from cerebral white matter disease (WMD. The concept is based on the original observation in 1999 of a correlation between the severity of leukoareosis or WMD, urinary symptoms, gait disorder and cognitive impairment. Over the last 20 years, the realization that WMD is not a benign incidental finding in the elderly has become generally accepted and several studies have pointed to an association between geriatric syndromes and this type of pathology. The main brunt of WMD is in the frontal regions, a region recognized to be crucial for bladder control. Other disorders should be excluded, both neurological and urological, such as normalpressure hydrocephalus, progressive supranuclear palsy, etc., and prostatic hyperplasia, physical stress incontinence, nocturnal polyuria, etc. Treatment involves management of small vessel disease risk factors and anticholinergic drugs that do not easily penetrate the blood brain barrier to improve bladder control.

A cataract-causing connexin 50 mutant is mislocalized to the ER due to loss of the fourth transmembrane domain and cytoplasmic domain.

Science.gov (United States)

Somaraju Chalasani, Madhavi Latha; Muppirala, Madhavi; G Ponnam, Surya Prakash; Kannabiran, Chitra; Swarup, Ghanshyam

2013-01-01

Mutations in the eye lens gap junction protein connexin 50 cause cataract. Earlier we identified a frameshift mutant of connexin 50 (c.670insA; p.Thr203AsnfsX47) in a family with autosomal recessive cataract. The mutant protein is smaller and contains 46 aberrant amino acids at the C-terminus after amino acid 202. Here, we have analysed this frameshift mutant and observed that it localized to the endoplasmic reticulum (ER) but not in the plasma membrane. Moreover, overexpression of the mutant resulted in disintegration of the ER-Golgi intermediate compartment (ERGIC), reduction in the level of ERGIC-53 protein and breakdown of the Golgi in many cells. Overexpression of the frameshift mutant partially inhibited the transport of wild type connexin 50 to the plasma membrane. A deletion mutant lacking the aberrant sequence showed predominant localization in the ER and inhibited anterograde protein transport suggesting, therefore, that the aberrant sequence is not responsible for improper localization of the frameshift mutant. Further deletion analysis showed that the fourth transmembrane domain and a membrane proximal region (231-294 amino acids) of the cytoplasmic domain are needed for transport from the ER and localization to the plasma membrane. Our results show that a frameshift mutant of connexin 50 mislocalizes to the ER and causes disintegration of the ERGIC and Golgi. We have also identified a sequence of connexin 50 crucial for transport from the ER and localization to the plasma membrane.

Subcellular distribution of swine vesicular disease virus proteins and alterations induced in infected cells: A comparative study with foot-and-mouth disease virus and vesicular stomatitis virus

International Nuclear Information System (INIS)

Martin-Acebes, Miguel A.; Gonzalez-Magaldi, Monica; Rosas, Maria F.; Borrego, Belen; Brocchi, Emiliana; Armas-Portela, Rosario; Sobrino, Francisco

2008-01-01

The intracellular distribution of swine vesicular disease virus (SVDV) proteins and the induced reorganization of endomembranes in IBRS-2 cells were analyzed. Fluorescence to new SVDV capsids appeared first upon infection, concentrated in perinuclear circular structures and colocalized to dsRNA. As in foot-and-mouth disease virus (FMDV)-infected cells, a vesicular pattern was predominantly found in later stages of SVDV capsid morphogenesis that colocalized with those of non-structural proteins 2C, 2BC and 3A. These results suggest that assembly of capsid proteins is associated to the replication complex. Confocal microscopy showed a decreased fluorescence to ER markers (calreticulin and protein disulfide isomerase), and disorganization of cis-Golgi gp74 and trans-Golgi caveolin-1 markers in SVDV- and FMDV-, but not in vesicular stomatitis virus (VSV)-infected cells. Electron microscopy of SVDV-infected cells at an early stage of infection revealed fragmented ER cisternae with expanded lumen and accumulation of large Golgi vesicles, suggesting alterations of vesicle traffic through Golgi compartments. At this early stage, FMDV induced different patterns of ER fragmentation and Golgi alterations. At later stages of SVDV cytopathology, cells showed a completely vacuolated cytoplasm containing vesicles of different sizes. Cell treatment with brefeldin A, which disrupts the Golgi complex, reduced SVDV (∼ 5 log) and VSV (∼ 4 log) titers, but did not affect FMDV growth. Thus, three viruses, which share target tissues and clinical signs in natural hosts, induce different intracellular effects in cultured cells

Regionalism, Regionalization and Regional Development

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Liviu C. Andrei

2016-03-01

Full Text Available Sustained development is a concept associating other concepts, in its turn, in the EU practice, e.g. regionalism, regionalizing and afferent policies, here including structural policies. This below text, dedicated to integration concepts, will limit on the other hand to regionalizing, otherwise an aspect typical to Europe and to the EU. On the other hand, two aspects come up to strengthen this field of ideas, i.e. the region (al-regionalism-(regional development triplet has either its own history or precise individual outline of terms.

GRASP55 Senses Glucose Deprivation through O-GlcNAcylation to Promote Autophagosome-Lysosome Fusion.

Science.gov (United States)

Zhang, Xiaoyan; Wang, Leibin; Lak, Behnam; Li, Jie; Jokitalo, Eija; Wang, Yanzhuang

2018-04-23

The Golgi apparatus is the central hub for protein trafficking and glycosylation in the secretory pathway. However, how the Golgi responds to glucose deprivation is so far unknown. Here, we report that GRASP55, the Golgi stacking protein located in medial- and trans-Golgi cisternae, is O-GlcNAcylated by the O-GlcNAc transferase OGT under growth conditions. Glucose deprivation reduces GRASP55 O-GlcNAcylation. De-O-GlcNAcylated GRASP55 forms puncta outside of the Golgi area, which co-localize with autophagosomes and late endosomes/lysosomes. GRASP55 depletion reduces autophagic flux and results in autophagosome accumulation, while expression of an O-GlcNAcylation-deficient mutant of GRASP55 accelerates autophagic flux. Biochemically, GRASP55 interacts with LC3-II on the autophagosomes and LAMP2 on late endosomes/lysosomes and functions as a bridge between LC3-II and LAMP2 for autophagosome and lysosome fusion; this function is negatively regulated by GRASP55 O-GlcNAcylation. Therefore, GRASP55 senses glucose levels through O-GlcNAcylation and acts as a tether to facilitate autophagosome maturation. Copyright © 2018 Elsevier Inc. All rights reserved.

Alpha-fetoprotein-L3 and Golgi protein 73 may serve as candidate biomarkers for diagnosing alpha-fetoprotein-negative hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

Zhang ZG

2015-12-01

Full Text Available Zhiguo Zhang,1 Yanying Zhang,2 Yeying Wang,1 Lingling Xu,3 Wanju Xu3 1Department of Clinical Laboratory, Zhangqiu Maternity and Child Care Hospital, Zhangqiu, 2Department of Clinical Laboratory, Zaozhuang City Wangkai Infection Hospital, Zaozhuang, 3Department of Clinical Laboratory, Qianfoshan Hospital, Jinan, People’s Republic of China Abstract: Currently, there is no reliable biomarker for use in diagnosing alpha-fetoprotein (AFP-negative hepatocellular carcinoma (HCC. Such a biomarker would aid in making an early diagnosis of AFP-negative HCC, ensuring the timely initiation of treatment. This study examined AFP-L3 and Golgi protein 73 (GP73 as candidate biomarkers for AFP-negative HCC. The affinity adsorption method and enzyme-linked immunoassays were separately used to determine serum levels of AFP-L3 and GP73 in 50 patients with AFP-negative HCC, 30 non-HCC patients, and 50 healthy subjects. Fifty percent of patients with AFP-negative HCC tested positive for AFP-L3, while 3.33% of non-HCC patients and 2.00% of healthy subjects were AFP-L3 positive. Patients with AFP-negative HCC had significantly higher serum levels of AFP-L3 compared to non-HCC patients and healthy individuals; however, there was no significant difference in the AFP-L3 levels of non-HCC patients and healthy subjects. Sixty-six percent of patients with AFP-negative HCC tested positive for GP73, while 10% of non-HCC patients and 0% of healthy subjects were GP73-positive. Patients with AFP-negative HCC had significantly higher serum levels of GP73 compared to non-HCC patients and healthy subjects, but there was no significant difference between the GP73 levels of non-HCC patients and healthy individuals. Moreover, 20 patients with AFP-negative HCC were both AFP-L3- and GP73-positive, while no non-HCC patients or healthy subjects tested positive for both markers. Either AFP-L3 or GP73 may be used as a biomarker for diagnosing AFP-negative HCC, while their combined use

Localization of high affinity [3H]glycine transport sites in the cerebellar cortex

International Nuclear Information System (INIS)

Wilkin, G.P.; Csillag, A.; Balazs, R.; Kingsbury, A.E.; Wilson, J.E.; Johnson, A.L.

1981-01-01

A study was made of [ 3 H ]glycine uptake sites in a preparation greatly enriched in large pieces of the cerebellar glomeruli (glomerulus particles) and in morphologically well preserved slices of rat cerebellum. Electron microscopic autoradiography revealed that of the neurones in the cerebellar cortex only Golgi cells transported [ 3 H]glycine at the low concentration used. Glial cells also took up [ 3 H]glycine but to a lesser extent than the Golgi neurons. It was also confirmed that under comparable conditions Golgi cells transport [ 3 H]GABA. Kinetic studies utilizing the Golgi axon terminal-containing glomerulus particles showed that glycine is a weak non-competitive inhibitor of [ 3 H]GABA uptake (Ksub(i) over 600 μM vs the Ksub(t) of about 20 μM) and that GABA is an even weaker inhibitor of [ 3 H]glycine uptake. (Auth.)

In 17q21.31 microdeletion syndrome, hypersocial behaviour may be part of the neuropsychological phenotype

NARCIS (Netherlands)

Egger, J.I.M.; Wingbermühle, P.A.M.; Dijkman, M.W.; Verhoeven, W.M.A.

2013-01-01

Objective: The 17q21.31 microdeletion encompasses among others the microtubule associated protein tau (MAPT) gene that is highly expressed in the brain and is involved in several neurodegenerative disorders such as fronto-temporal dementias and progressive supranuclear palsy. It can be postulated

Statistic rCBF study of extrapyramidal disorders

Energy Technology Data Exchange (ETDEWEB)

Kamei, Hiroshi; Nakajima, Takashi; Fukuhara, Nobuyoshi [National Saigata Hospital, Ogata, Niigata (Japan)

2002-08-01

We studied regional cerebral blood flow (rCBF) in 16 patients with Parkinson's disease (PD), 2 patients with dementia with Lewy bodies (DLB), 2 patients with progressive supranuclear palsy (PSP), 2 patients with striatonigral degeneration, and 16 normal volunteers, using Three-dimensional stereotactic surface projections (3D-SSP). Decreased rCBF in PD patients was shown in the posterior parietal and occipital cortex. Decreased rCBF in DLB was shown in the frontal, parietal and occipital cortex with relative sparing of the sensorimotor cortex.. Decreased rCBF in PSP was shown in the frontal cortex. Decreased rCBF in SND was shown in the frontal cortex and cerebellum. Statistic rCBF analysis using 3D-SSP was a useful measure for the early differential diagnosis of extrapyramidal disorders. (author)

GADD34 Function in Protein Trafficking Promotes Adaptation to Hyperosmotic Stress in Human Corneal Cells

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Dawid Krokowski

2017-12-01

Full Text Available Summary: GADD34, a stress-induced regulatory subunit of the phosphatase PP1, is known to function in hyperosmotic stress through its well-known role in the integrated stress response (ISR pathway. Adaptation to hyperosmotic stress is important for the health of corneal epithelial cells exposed to changes in extracellular osmolarity, with maladaptation leading to dry eye syndrome. This adaptation includes induction of SNAT2, an endoplasmic reticulum (ER-Golgi-processed protein, which helps to reverse the stress-induced loss of cell volume and promote homeostasis through amino acid uptake. Here, we show that GADD34 promotes the processing of proteins synthesized on the ER during hyperosmotic stress independent of its action in the ISR. We show that GADD34/PP1 phosphatase activity reverses hyperosmotic-stress-induced Golgi fragmentation and is important for cis- to trans-Golgi trafficking of SNAT2, thereby promoting SNAT2 plasma membrane localization and function. These results suggest that GADD34 is a protective molecule for ocular diseases such as dry eye syndrome. : Here, Krokowski et al. show that GADD34/PP1 protects the microtubule network, prevents Golgi fragmentation, and preserves protein trafficking independent of its action in the integrated stress response (ISR. In osmoadaptation, GADD34 facilitates trans-Golgi-mediated processing of the endoplasmic reticulum (ER-synthesized amino acid transporter SNAT2, which in turn increases amino acid uptake. Keywords: SNAT2, GADD34, hyperosmotic stress, amino acid transport, Golgi fragmentation, ISR

A route for direct retinal input to the preoptic hypothalamus: dendritic projections into the optic chiasm.

Science.gov (United States)

Silver, J; Brand, S

1979-07-01

With the use of Golgi, horseradish peroxidase, and electron microscopic techniques, neurons within a broad region of the preoptic hypothalamus of the mouse were shown to have dendrites that projected well into the depths of the optic chiasm. Further experimental and ultrastructural investigation demonstrated synapses between these dendrites and retinal axonal boutons within the chiasm. All synapses located in the chiasm were classified as Gray's type I. The possible function of these dendritic projections is discussed.

Sequence Classification: 893846 [

Lifescience Database Archive (English)

Full Text Available ds zinc, found both on membranes and in the cytosol; guanine nucleotide dissociation stimulator; Dss4p || http://www.ncbi.nlm.nih.gov/protein/6325274 ... ...tide release factor functioning in the post-Golgi secretory pathway, required for ER-to-Golgi transport, bin

ORIGINAL ARTICLES

African Journals Online (AJOL)

(TW) or adjacent cytoplasm, in round or bizarre-shaped dense bodies. (double arrows), and in the Golgi complex (G) microvilli (MV). (x 120000). these haemosiderin-containing structures were acid- phosphatase-positive and were therefore secondary lysosomes. Although the Golgi complex in pellagra patients occasionally.

Progressive Supranuclear Palsy (PSP): Frequently Asked Questions

Science.gov (United States)

... PSP in some cases. Sinemet. This is the brand name for a combination of “levodopa” and “carbidopa.” ... A major goal of CurePSP is to increase awareness of PSP, CBD, MSA and related brain diseases ...

Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis

International Nuclear Information System (INIS)

Vasconcellos, Luiz Felipe Rocha; Novis, Sergio A. Pereira; Rosso, Ana Lucia Z.; Moreira, Denise Madeira

2009-01-01

The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinson's disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type), and 10 individuals without any psychiatric or neurological disorders (controls). Clinical scales included Hoenh and Yahr, unified Parkinson's disease rating scale and mini mental status examination. The results showed that patients with Parkinson's disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism. (author)

Na+/K+-ATPase inhibition partially mimics the ethanol-induced increase of the Golgi cell-dependent component of the tonic GABAergic current in rat cerebellar granule cells.

Directory of Open Access Journals (Sweden)

Marvin R Diaz

Full Text Available Cerebellar granule cells (CGNs are one of many neurons that express phasic and tonic GABAergic conductances. Although it is well established that Golgi cells (GoCs mediate phasic GABAergic currents in CGNs, their role in mediating tonic currents in CGNs (CGN-I(tonic is controversial. Earlier studies suggested that GoCs mediate a component of CGN-I(tonic that is present only in preparations from immature rodents. However, more recent studies have detected a GoC-dependent component of CGN-I(tonic in preparations of mature rodents. In addition, acute exposure to ethanol was shown to potentiate the GoC component of CGN-I(tonic and to induce a parallel increase in spontaneous inhibitory postsynaptic current frequency at CGNs. Here, we tested the hypothesis that these effects of ethanol on GABAergic transmission in CGNs are mediated by inhibition of the Na(+/K(+-ATPase. We used whole-cell patch-clamp electrophysiology techniques in cerebellar slices of male rats (postnatal day 23-30. Under these conditions, we reliably detected a GoC-dependent component of CGN-I(tonic that could be blocked with tetrodotoxin. Further analysis revealed a positive correlation between basal sIPSC frequency and the magnitude of the GoC-dependent component of CGN-I(tonic. Inhibition of the Na(+/K(+-ATPase with a submaximal concentration of ouabain partially mimicked the ethanol-induced potentiation of both phasic and tonic GABAergic currents in CGNs. Modeling studies suggest that selective inhibition of the Na(+/K(+-ATPase in GoCs can, in part, explain these effects of ethanol. These findings establish a novel mechanism of action of ethanol on GABAergic transmission in the central nervous system.

Complex structure of the fission yeast SREBP-SCAP binding domains reveals an oligomeric organization.

Science.gov (United States)

Gong, Xin; Qian, Hongwu; Shao, Wei; Li, Jingxian; Wu, Jianping; Liu, Jun-Jie; Li, Wenqi; Wang, Hong-Wei; Espenshade, Peter; Yan, Nieng

2016-11-01

Sterol regulatory element-binding protein (SREBP) transcription factors are master regulators of cellular lipid homeostasis in mammals and oxygen-responsive regulators of hypoxic adaptation in fungi. SREBP C-terminus binds to the WD40 domain of SREBP cleavage-activating protein (SCAP), which confers sterol regulation by controlling the ER-to-Golgi transport of the SREBP-SCAP complex and access to the activating proteases in the Golgi. Here, we biochemically and structurally show that the carboxyl terminal domains (CTD) of Sre1 and Scp1, the fission yeast SREBP and SCAP, form a functional 4:4 oligomer and Sre1-CTD forms a dimer of dimers. The crystal structure of Sre1-CTD at 3.5 Å and cryo-EM structure of the complex at 5.4 Å together with in vitro biochemical evidence elucidate three distinct regions in Sre1-CTD required for Scp1 binding, Sre1-CTD dimerization and tetrameric formation. Finally, these structurally identified domains are validated in a cellular context, demonstrating that the proper 4:4 oligomeric complex formation is required for Sre1 activation.

Molecular aspects of GAPR-1 interactions with biological and model membranes

NARCIS (Netherlands)

van Galen, J.

2008-01-01

Golgi-Associated Plant Pathogenesis-Related protein 1 (GAPR-1) is a mammalian protein that belongs to the superfamily of plant pathogenesis related proteins group 1 (PR-1). It is a peripheral membrane protein that strongly associates with the cytosolic leaflet of Golgi membranes and is enriched in

Functional assays for the assessment of the pathogenicity of variants of GOSR2, an ER-to-Golgi SNARE involved in progressive myoclonus epilepsies

Directory of Open Access Journals (Sweden)

Jörn M. Völker

2017-12-01

Full Text Available Progressive myoclonus epilepsies (PMEs are inherited disorders characterized by myoclonus, generalized tonic-clonic seizures, and ataxia. One of the genes that is associated with PME is the ER-to-Golgi Qb-SNARE GOSR2, which forms a SNARE complex with syntaxin-5, Bet1 and Sec22b. Most PME patients are homo­zygous for a p.Gly144Trp mutation and develop similar clinical presentations. Recently, a patient who was compound heterozygous for p.Gly144Trp and a previously unseen p.Lys164del mutation was identified. Because this patient presented with a milder disease phenotype, we hypothesized that the p.Lys164del mutation may be less severe compared to p.Gly144Trp. To characterize the effect of the p.Gly144Trp and p.Lys164del mutations, both of which are present in the SNARE motif of GOSR2, we examined the corresponding mutations in the yeast ortholog Bos1. Yeasts expressing the orthologous mutants in Bos1 showed impaired growth, suggesting a partial loss of function, which was more severe for the Bos1 p.Gly176Trp mutation. Using anisotropy and gel filtration, we report that Bos1 p.Gly176Trp and p.Arg196del are capable of complex formation, but with partly reduced activity. Molecular dynamics (MD simulations showed that the hydrophobic core, which triggers SNARE complex formation, is compromised due to the glycine-to-tryptophan substitution in both GOSR2 and Bos1. In contrast, the deletion of residue p.Lys164 (or p.Arg196del in Bos1 interferes with the formation of hydrogen bonds between GOSR2 and syntaxin-5. Despite these perturbations, all SNARE complexes stayed intact during longer simulations. Thus, our data suggest that the milder course of disease in compound heterozygous PME is due to less severe impairment of the SNARE function.

Characterization of ATP7A missense mutants suggests a correlation between intracellular trafficking and severity of Menkes disease

DEFF Research Database (Denmark)

Skjørringe, Tina; Pedersen, Per Amstrup; Thorborg, Sidsel Salling

2017-01-01

Menkes disease (MD) is caused by mutations in ATP7A, encoding a copper-transporting P-type ATPase which exhibits copper-dependent trafficking. ATP7A is found in the Trans-Golgi Network (TGN) at low copper concentrations, and in the post-Golgi compartments and the plasma membrane at higher...

Activation of Rab GTPase Sec4 by its GEF Sec2 is required for prospore membrane formation during sporulation in yeast Saccharomyces cerevisiae.

Science.gov (United States)

Suda, Yasuyuki; Tachikawa, Hiroyuki; Inoue, Ichiro; Kurita, Tomokazu; Saito, Chieko; Kurokawa, Kazuo; Nakano, Akihiko; Irie, Kenji

2018-02-01

Sec2 activates Sec4 Rab GTPase as a guanine nucleotide exchange factor for the recruitment of downstream effectors to facilitate tethering and fusion of post-Golgi vesicles at the plasma membrane. During the meiosis and sporulation of budding yeast, post-Golgi vesicles are transported to and fused at the spindle pole body (SPB) to form a de novo membrane, called the prospore membrane. Previous studies have revealed the role of the SPB outer surface called the meiotic outer plaque (MOP) in docking and fusion of post-Golgi vesicles. However, the upstream molecular machinery for post-Golgi vesicular fusion that facilitates prospore membrane formation remains enigmatic. Here, we demonstrate that the GTP exchange factor for Sec4, Sec2, participates in the formation of the prospore membrane. A conditional mutant in which the SEC2 expression is shut off during sporulation showed sporulation defects. Inactivation of Sec2 caused Sec4 targeting defects along the prospore membranes, thereby causing insufficient targeting of downstream effectors and cargo proteins to the prospore membrane. These results suggest that the activation of Sec4 by Sec2 is required for the efficient supply of post-Golgi vesicles to the prospore membrane and thus for prospore membrane formation/extension and subsequent deposition of spore wall materials. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Intracellular and transcellular transport of secretory and membrane proteins in the rat hepatocyte

International Nuclear Information System (INIS)

Sztul, E.S.

1984-01-01

The intra- and transcellular transport of hepatic secretory and membrane proteins was studied in rats in vivo using [ 3 H]fucose and [ 35 S]cyteine as metabolic precursors. Incorporated radioactivity in plasma, bile, and liver subcellular fractions was measured and the labeled proteins of the Golgi complex, bile and plasma were separated by SDS-PAGE and identified by fluorography. 3 H-radioactivity in Golgi fractions peaked at 10 min post injection (p.i.) and then declined concomitantly with the appearance of labeled glycoproteins in plasma. Maximal secretion of secretory fucoproteins from the Golgi complex occurred between 10 and 20 min p.i. In contrast, the clearance of labeled proteins from Golgi membrane subfractions occurred past 30 min p.i., indicating that membrane proteins leave the Golgi complex at least 10 min later than the bulk of content proteins. A major 80K form of Secretory Component (SC) was identified in the bile by precipitation with an anti IgA antibody. A comparative study of kinetics of transport of 35 S-labeled SC and 35 S-labeled albumin showed that albumin peaked in bile at ∼45 min p.i., whereas the SC peak occurred at 80 min p.i., suggesting that the transit time differs for plasma and membrane proteins which are delivered to the bile canaliculus (BC)

Golga5 is dispensable for mouse embryonic development and postnatal survival.

Science.gov (United States)

McGee, Lynessa J; Jiang, Alex L; Lan, Yu

2017-07-01

Golgins are a family of coiled-coil proteins located at the cytoplasmic surface of the Golgi apparatus and have been implicated in maintaining Golgi structural integrity through acting as tethering factors for retrograde vesicle transport. Whereas knockdown of several individual golgins in cultured cells caused Golgi fragmentation and disruption of vesicle trafficking, analysis of mutant mouse models lacking individual golgins have discovered tissue-specific developmental functions. Recently, homozygous loss of function of GOLGA2, of which previous in vitro studies suggested an essential role in maintenance of Golgi structure and in mitosis, has been associated with a neuromuscular disorder in human patients, which highlights the need for understanding the developmental roles of the golgins in vivo. We report here generation of Golga5-deficient mice using CRISPR/Cas9-mediated genome editing. Although knockdown studies in cultured cells have implicated Golga5 in maintenance of Golgi organization, we show that Golga5 is not required for mouse embryonic development, postnatal survival, or fertility. Moreover, whereas Golga5 is structurally closely related to Golgb1, we show that inactivation of Golga5 does not enhance the severity of developmental defects in Golgb1-deficient mice. The Golga5-deficient mice enable further investigation of the roles and functional specificity of golgins in development and diseases. © 2017 Wiley Periodicals, Inc.

Neutron Stars and Black Holes New clues from Chandra and XMM-Newton

CERN Multimedia

CERN. Geneva. Audiovisual Unit

2002-01-01

Neutron stars and black holes, the most compact astrophysical objects, have become observable in many different ways during the last few decades. We will first review the phenomenology and properties of neutron stars and black holes (stellar and supermassive) as derived from multiwavelength observatories. Recently much progress has been made by means of the new powerful X-ray observatories Chandra and XMM-Newton which provide a substantial increase in sensitivity as well as spectral and angular resolution compared with previous satellites like ROSAT and ASCA. We shall discuss in more detail two recent topics: (1) The attempts to use X-ray spectroscopy for measuring the radii of neutron stars which depend on the equation of state at supranuclear densities. Have quark stars been detected? (2) The diagnostics of the strong gravity regions around supermassive black holes using X-ray spectroscopy.

Co-localization of glycine and gaba immunoreactivity in interneurons in Macaca monkey cerebellar cortex.

Science.gov (United States)

Crook, J; Hendrickson, A; Robinson, F R

2006-09-15

Previous work demonstrates that the cerebellum uses glycine as a fast inhibitory neurotransmitter [Ottersen OP, Davanger S, Storm-Mathisen J (1987) Glycine-like immunoreactivity in the cerebellum of rat and Senegalese baboon, Papio papio: a comparison with the distribution of GABA-like immunoreactivity and with [3H]glycine and [3H]GABA uptake. Exp Brain Res 66(1):211-221; Ottersen OP, Storm-Mathisen J, Somogyi P (1988) Colocalization of glycine-like and GABA-like immunoreactivities in Golgi cell terminals in the rat cerebellum: a postembedding light and electron microscopic study. Brain Res 450(1-2):342-353; Dieudonne S (1995) Glycinergic synaptic currents in Golgi cells of the rat cerebellum. Proc Natl Acad Sci U S A 92:1441-1445; Dumoulin A, Triller A, Dieudonne S (2001) IPSC kinetics at identified GABAergic and mixed GABAergic and glycinergic synapses onto cerebellar Golgi cells. J Neurosci 21(16):6045-6057; Dugue GP, Dumoulin A, Triller A, Dieudonne S (2005) Target-dependent use of coreleased inhibitory transmitters at central synapses. J Neurosci 25(28):6490-6498; Zeilhofer HU, Studler B, Arabadzisz D, Schweizer C, Ahmadi S, Layh B, Bosl MR, Fritschy JM (2005) Glycinergic neurons expressing enhanced green fluorescent protein in bacterial artificial chromosome transgenic mice. J Comp Neurol 482(2):123-141]. In the rat cerebellum glycine is not released by itself but is released together with GABA by Lugaro cells onto Golgi cells [Dumoulin A, Triller A, Dieudonne S (2001) IPSC kinetics at identified GABAergic and mixed GABAergic and glycinergic synapses onto cerebellar Golgi cells. J Neurosci 21(16):6045-6057] and by Golgi cells onto unipolar brush and granule cells [Dugue GP, Dumoulin A, Triller A, Dieudonne S (2005) Target-dependent use of coreleased inhibitory transmitters at central synapses. J Neurosci 25(28):6490-6498]. Here we report, from immunolabeling evidence in Macaca cerebellum, that interneurons in the granular cell layer are glycine+ at a density

Yeast Interacting Proteins Database: YNL258C, YKR022C [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available YNL258C DSL1 Peripheral membrane protein required for Golgi-to-ER retrograde traffi...equired for Golgi-to-ER retrograde traffic; component of the ER target site that interacts with coatomer, th...it ORF YNL258C Bait gene name DSL1 Bait description Peripheral membrane protein r

Brain monoamine oxidase B and A in human parkinsonian dopamine deficiency disorders.

Science.gov (United States)

Tong, Junchao; Rathitharan, Gausiha; Meyer, Jeffrey H; Furukawa, Yoshiaki; Ang, Lee-Cyn; Boileau, Isabelle; Guttman, Mark; Hornykiewicz, Oleh; Kish, Stephen J

2017-09-01

See Jellinger (doi:10.1093/awx190) for a scientific commentary on this article. The enzyme monoamine oxidases (B and A subtypes, encoded by MAOB and MAOA, respectively) are drug targets in the treatment of Parkinson's disease. Inhibitors of MAOB are used clinically in Parkinson's disease for symptomatic purposes whereas the potential disease-modifying effect of monoamine oxidase inhibitors is debated. As astroglial cells express high levels of MAOB, the enzyme has been proposed as a brain imaging marker of astrogliosis, a cellular process possibly involved in Parkinson's disease pathogenesis as elevation of MAOB in astrocytes might be harmful. Since brain monoamine oxidase status in Parkinson's disease is uncertain, our objective was to measure, by quantitative immunoblotting in autopsied brain homogenates, protein levels of both monoamine oxidases in three different degenerative parkinsonian disorders: Parkinson's disease (n = 11), multiple system atrophy (n = 11), and progressive supranuclear palsy (n = 16) and in matched controls (n = 16). We hypothesized that if MAOB is 'substantially' localized to astroglial cells, MAOB levels should be generally associated with standard astroglial protein measures (e.g. glial fibrillary acidic protein). MAOB levels were increased in degenerating putamen (+83%) and substantia nigra (+10%, non-significant) in multiple system atrophy; in caudate (+26%), putamen (+27%), frontal cortex (+31%) and substantia nigra (+23%) of progressive supranuclear palsy; and in frontal cortex (+33%), but not in substantia nigra of Parkinson's disease, a region we previously reported no increase in astrocyte protein markers. Although the magnitude of MAOB increase was less than those of standard astrocytic markers, significant positive correlations were observed amongst the astrocyte proteins and MAOB. Despite suggestions that MAOA (versus MAOB) is primarily responsible for metabolism of dopamine in dopamine neurons, there was no loss of the

The evolution of primary progressive apraxia of speech.

Science.gov (United States)

Josephs, Keith A; Duffy, Joseph R; Strand, Edythe A; Machulda, Mary M; Senjem, Matthew L; Gunter, Jeffrey L; Schwarz, Christopher G; Reid, Robert I; Spychalla, Anthony J; Lowe, Val J; Jack, Clifford R; Whitwell, Jennifer L

2014-10-01

Primary progressive apraxia of speech is a recently described neurodegenerative disorder in which patients present with an isolated apraxia of speech and show focal degeneration of superior premotor cortex. Little is known about how these individuals progress over time, making it difficult to provide prognostic estimates. Thirteen subjects with primary progressive apraxia of speech underwent two serial comprehensive clinical and neuroimaging evaluations 2.4 years apart [median age of onset = 67 years (range: 49-76), seven females]. All underwent detailed speech and language, neurological and neuropsychological assessments, and magnetic resonance imaging, diffusion tensor imaging and (18)F-fluorodeoxyglucose positron emission tomography at both baseline and follow-up. Rates of change of whole brain, ventricle, and midbrain volumes were calculated using the boundary-shift integral and atlas-based parcellation, and rates of regional grey matter atrophy were assessed using tensor-based morphometry. White matter tract degeneration was assessed on diffusion-tensor imaging at each time-point. Patterns of hypometabolism were assessed at the single subject-level. Neuroimaging findings were compared with a cohort of 20 age, gender, and scan-interval matched healthy controls. All subjects developed extrapyramidal signs. In eight subjects the apraxia of speech remained the predominant feature. In the other five there was a striking progression of symptoms that had evolved into a progressive supranuclear palsy-like syndrome; they showed a combination of severe parkinsonism, near mutism, dysphagia with choking, vertical supranuclear gaze palsy or slowing, balance difficulties with falls and urinary incontinence, and one was wheelchair bound. Rates of whole brain atrophy (1.5% per year; controls = 0.4% per year), ventricular expansion (8.0% per year; controls = 3.3% per year) and midbrain atrophy (1.5% per year; controls = 0.1% per year) were elevated (P ≤ 0.001) in all 13

Positron emission tomography in degenerative disorders of the dopaminergic system

Energy Technology Data Exchange (ETDEWEB)

Karbe, H; Holthoff, V; Huber, M; Herholz, K; Wienhard, K; Wagner, R; Heiss, W D [Universitaetsklinik fuer Neurologie und Max-Planck-Institut fuer neurologische Forschung, Koeln (Germany)

1992-01-01

21 patients who had Parkinson's disease (PD), PD plus dementia of Alzheimer type (PDAT) or progressive supranuclear palsy (PSP), were studied with positron emission tomography (PET) using ({sup 18}F)-2-fluoro-2-deoxy-D-glucose (FDG). In one patient with strictly unilateral PD side differences in striatal dopa uptake were studied with 6-({sup 18}F)fluoro-L-dopa (F-dopa). In patients with PD PET with FDG did not show any significant change in regional cerebral metabolic rates for glucose (rCMR(Glu)). In PDAT glucose metabolism was generally reduced, the most severe decrease was found in parietal cortex. The metabolic pattern was similar to that typically found in patients with Alzheimer's disease (AD). In the patient with strictly unilateral PD rCMR(Glu) was normal, F-dopa PET, however, revealed a distinct reduction of dopa uptake in the contralateral putamen. In PSP glucose metabolism was significantly decreased in subcortical regions (caudatum, putamen and brainstem) and in frontal cortex. Thus PET demonstrated a clear difference of metabolic pattern between PDAT and PSP. (authors).

Cogan’s anterior internuclear ophthalmoplegia in young Ethiopian

African Journals Online (AJOL)

Yeshigeta Gelaw

2014-06-16

Jun 16, 2014 ... Supranuclear ocular motor disorders can be caused by brain- stem, cerebellar or ... in the left eye and ataxic abducting nystagmus in the right eye on right gaze ... The gender (female sex) of the patient is also another supportive risk ... precede, occur concurrently with, or follow the development of bilateral ...

Identification of ER Proteins Involved in the Functional Organisation of the Early Secretory Pathway in Drosophila Cells by a Targeted RNAi Screen

Science.gov (United States)

Kondylis, Vangelis; Tang, Yang; Fuchs, Florian; Boutros, Michael; Rabouille, Catherine

2011-01-01

Background In Drosophila, the early secretory apparatus comprises discrete paired Golgi stacks in close proximity to exit sites from the endoplasmic reticulum (tER sites), thus forming tER-Golgi units. Although many components involved in secretion have been identified, the structural components sustaining its organisation are less known. Here we set out to identify novel ER resident proteins involved in the of tER-Golgi unit organisation. Results To do so, we designed a novel screening strategy combining a bioinformatics pre-selection with an RNAi screen. We first selected 156 proteins exhibiting known or related ER retention/retrieval signals from a list of proteins predicted to have a signal sequence. We then performed a microscopy-based primary and confirmation RNAi screen in Drosophila S2 cells directly scoring the organisation of the tER-Golgi units. We identified 49 hits, most of which leading to an increased number of smaller tER-Golgi units (MG for “more and smaller Golgi”) upon depletion. 16 of them were validated and characterised, showing that this phenotype was not due to an inhibition in secretion, a block in G2, or ER stress. Interestingly, the MG phenotype was often accompanied by an increase in the cell volume. Out of 6 proteins, 4 were localised to the ER. Conclusions This work has identified novel proteins involved in the organisation of the Drosophila early secretory pathway. It contributes to the effort of assigning protein functions to gene annotation in the secretory pathway, and analysis of the MG hits revealed an enrichment of ER proteins. These results suggest a link between ER localisation, aspects of cell metabolism and tER-Golgi structural organisation. PMID:21383842

Enhanced SCAP glycosylation by inflammation induces macrophage foam cell formation.

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Chao Zhou

Full Text Available Inflammatory stress promotes foam cell formation by disrupting LDL receptor feedback regulation in macrophages. Sterol Regulatory Element Binding Proteins (SREBPs Cleavage-Activating Protein (SCAP glycosylation plays crucial roles in regulating LDL receptor and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCoAR feedback regulation. The present study was to investigate if inflammatory stress disrupts LDL receptor and HMGCoAR feedback regulation by affecting SCAP glycosylation in THP-1 macrophages. Intracellular cholesterol content was assessed by Oil Red O staining and quantitative assay. The expression of molecules controlling cholesterol homeostasis was examined using real-time quantitative RT-PCR and Western blotting. The translocation of SCAP from the endoplasmic reticulum (ER to the Golgi was detected by confocal microscopy. We demonstrated that exposure to inflammatory cytokines increased lipid accumulation in THP-1 macrophages, accompanying with an increased SCAP expression even in the presence of a high concentration of LDL. These inflammatory cytokines also prolonged the half-life of SCAP by enhancing glycosylation of SCAP due to the elevated expression of the Golgi mannosidase II. This may enhance translocation and recycling of SCAP between the ER and the Golgi, escorting more SREBP2 from the ER to the Golgi for activation by proteolytic cleavages as evidenced by an increased N-terminal of SREBP2 (active form. As a consequence, the LDL receptor and HMGCoAR expression were up-regulated. Interestingly, these effects could be blocked by inhibitors of Golgi mannosidases. Our results indicated that inflammation increased native LDL uptake and endogenous cholesterol de novo synthesis, thereby causing foam cell formation via increasing transcription and protein glycosylation of SCAP in macrophages. These data imply that inhibitors of Golgi processing enzymes might have a potential vascular-protective role in prevention of atherosclerotic foam

Enzymology and Molecular Biology of Cell Wall Biosynthesis. Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Dr. Peter M. Ray

2000-04-01

The following aspects of enzymology of cell wall synthesis were pursued under this cited grant: (1) Isolation of plasma membrane-localized glucan synthase II (GS-II) of pea; (2) Cloning of genes for possible plant GS-II components; (3) Golgi glucan synthase-I (GS-I); and (4) Golgi reversibly glycosylated protein 1 (RGP1).

Direct binding of retromer to human papillomavirus type 16 minor capsid protein L2 mediates endosome exit during viral infection.

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Andreea Popa

2015-02-01

Full Text Available Trafficking of human papillomaviruses to the Golgi apparatus during virus entry requires retromer, an endosomal coat protein complex that mediates the vesicular transport of cellular transmembrane proteins from the endosome to the Golgi apparatus or the plasma membrane. Here we show that the HPV16 L2 minor capsid protein is a retromer cargo, even though L2 is not a transmembrane protein. We show that direct binding of retromer to a conserved sequence in the carboxy-terminus of L2 is required for exit of L2 from the early endosome and delivery to the trans-Golgi network during virus entry. This binding site is different from known retromer binding motifs and can be replaced by a sorting signal from a cellular retromer cargo. Thus, HPV16 is an unconventional particulate retromer cargo, and retromer binding initiates retrograde transport of viral components from the endosome to the trans-Golgi network during virus entry. We propose that the carboxy-terminal segment of L2 protein protrudes through the endosomal membrane and is accessed by retromer in the cytoplasm.

Alzheimer's disease amyloid-beta links lens and brain pathology in Down syndrome.

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Juliet A Moncaster

2010-05-01

Full Text Available Down syndrome (DS, trisomy 21 is the most common chromosomal disorder and the leading genetic cause of intellectual disability in humans. In DS, triplication of chromosome 21 invariably includes the APP gene (21q21 encoding the Alzheimer's disease (AD amyloid precursor protein (APP. Triplication of the APP gene accelerates APP expression leading to cerebral accumulation of APP-derived amyloid-beta peptides (Abeta, early-onset AD neuropathology, and age-dependent cognitive sequelae. The DS phenotype complex also includes distinctive early-onset cerulean cataracts of unknown etiology. Previously, we reported increased Abeta accumulation, co-localizing amyloid pathology, and disease-linked supranuclear cataracts in the ocular lenses of subjects with AD. Here, we investigate the hypothesis that related AD-linked Abeta pathology underlies the distinctive lens phenotype associated with DS. Ophthalmological examinations of DS subjects were correlated with phenotypic, histochemical, and biochemical analyses of lenses obtained from DS, AD, and normal control subjects. Evaluation of DS lenses revealed a characteristic pattern of supranuclear opacification accompanied by accelerated supranuclear Abeta accumulation, co-localizing amyloid pathology, and fiber cell cytoplasmic Abeta aggregates (approximately 5 to 50 nm identical to the lens pathology identified in AD. Peptide sequencing, immunoblot analysis, and ELISA confirmed the identity and increased accumulation of Abeta in DS lenses. Incubation of synthetic Abeta with human lens protein promoted protein aggregation, amyloid formation, and light scattering that recapitulated the molecular pathology and clinical features observed in DS lenses. These results establish the genetic etiology of the distinctive lens phenotype in DS and identify the molecular origin and pathogenic mechanism by which lens pathology is expressed in this common chromosomal disorder. Moreover, these findings confirm increased Abeta

A rare case of concomitant sicca keratopathy and ipsilateral central facial palsy in Wallenberg’s dorsolateral medullary syndrome

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De Bruyn, Deborah

2017-03-01

Full Text Available Objective: To describe a patient with a right-sided supranuclear facial palsy and concomitant sicca keratopathy of the right eye following right-sided dorsolateral medullary infarction. Methods: Our patient underwent a complete ophthalmologic and neurologic examination including biomicroscopy, fundus examination, cranial nerve examination, Shirmer I test, and magnetic resonance imaging of the brain.Results: A 61-year-old woman presented in emergency with a central facial nerve palsy on the right side and truncal ataxia. Neurologic assessment revealed a concurrent dysphagia, dysarthria, hypoesthesia of the right face, and weakness of the right upper limb. Magnetic resonance imaging of the brain showed an old left-sided cerebellar infarction, but a recent ischemic infarction at the level of the right dorsolateral medulla oblongata was the cause of our patient’s current problems. One month after diagnosis of the right-sided dorsolateral medullary syndrome, there were complaints of ocular irritation and a diminished visual acuity in the right eye. Biomicroscopy showed a sicca keratopathy with nearly complete absence of tear secretion on the Shirmer I test, but with normal eye closure and preserved corneal reflexes and sensitivity.Conclusion: A dorsolateral medullary syndrome can have a variable expression in symptomatology. Our case is special because of the combination of an ipsilateral supranuclear facial palsy with normal upper facial muscle function together with an ipsilateral sicca keratopathy as a result of a nearly absent tear secretion. We hypothesized that the mechanism underlying the patient’s sicca keratopathy ipsilateral to the supranuclear facial palsy involved the superior salivatory nucleus, which is situated in the caudal pons inferiorly of the motor facial nucleus and is most probably affected by a superior extension of the infarcted area in the right medulla oblongata.

A case of double depressor palsy followed by pursuit deficit due to sequential infarction in bilateral thalamus and right medial superior temporal area.

Science.gov (United States)

Kim, Su Jin; Yeom, Myeong In; Lee, Seung Uk

2017-12-01

We present a unique case of a patient who suffered two rare events affecting the supranuclear control, first of the vertical and second of the horizontal eye movements. The first event involved bilateral thalamic infarcts that resulted in double depressor palsy. The second event occurred 1 year later and it involved supranuclear control of horizontal eye movements creating pursuit deficit. A 47-year-old male presented with complaints of diplopia upon awakening. He had atrial fibrillation, mitral valve regurgitation, aortic valve regurgitation, and a history of spleen infarction 1 year ago. His right eye was hypertrophic and right eye downgaze was limited unilaterally of equal degree in adduction and abduction. The patient was diagnosed with double depressor palsy of the right eye. Magnetic resonance imaging (MRI) of the brain showed an old infarction of the left thalamus, and diffusion MRI showed acute infarction of the right thalamus. The patient's daily warfarin dose was 2 mg and it was increased to 5 mg with cilostazol 75 mg twice a day. Seven weeks later, the patient's ocular movement revealed near normal muscle action, and subjectively, the patient was diplopia free. At follow-up 12 months later, the patient revisited the hospital because of sudden onset of blurred vision on right gaze. He was observed to have smooth pursuit deficit to the right side, and orthophoric position of the eyes in primary gaze. MRI of the brain showed an acute infarction in the right medial superior temporal area. The patient experienced very rare abnormal eyeball movements twice. This case highlights the importance of evaluating vertical movement of the eyes and vascular supplies when patients present with depressor deficit and supports the theory of a supranuclear function in patients who present with pursuit deficit.

Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis

Energy Technology Data Exchange (ETDEWEB)

Vasconcellos, Luiz Felipe Rocha [1Hospital dos Servidores do Estado, Rio de Janeiro RJ (Brazil)], e-mail: luizneurol@terra.com.br; Novis, Sergio A. Pereira; Rosso, Ana Lucia Z. [Hospital Universitario Clementino Fraga Filho (HUCFF), Rio de Janeiro, RJ (Brazil); Moreira, Denise Madeira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Neurologia Deolindo Couto; Leite, Ana Claudia C.B. [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

2009-03-15

The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinson's disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type), and 10 individuals without any psychiatric or neurological disorders (controls). Clinical scales included Hoenh and Yahr, unified Parkinson's disease rating scale and mini mental status examination. The results showed that patients with Parkinson's disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism. (author)

Interaction between the triglyceride lipase ATGL and the arf1 activator GBF1

KAUST Repository

Ellong, Emy Njoh

2011-07-18

The Arf1 exchange factor GBF1 (Golgi Brefeldin A resistance factor 1) and its effector COPI are required for delivery of ATGL (adipose triglyceride lipase) to lipid droplets (LDs). Using yeast two hybrid, co-immunoprecipitation in mammalian cells and direct protein binding approaches, we report here that GBF1 and ATGL interact directly and in cells, through multiple contact sites on each protein. The C-terminal region of ATGL interacts with N-terminal domains of GBF1, including the catalytic Sec7 domain, but not with full-length GBF1 or its entire N-terminus. The N-terminal lipase domain of ATGL (called the patatin domain) interacts with two C-terminal domains of GBF1, HDS (Homology downstream of Sec7) 1 and HDS2. These two domains of GBF1 localize to lipid droplets when expressed alone in cells, but not to the Golgi, unlike the full-length GBF1 protein, which localizes to both. We suggest that interaction of GBF1 with ATGL may be involved in the membrane trafficking pathway mediated by GBF1, Arf1 and COPI that contributes to the localization of ATGL to lipid droplets.

Interaction between the triglyceride lipase ATGL and the arf1 activator GBF1

KAUST Repository

Ellong, Emy Njoh; Soni, Krishnakant G.; Bui, Quynh-Trang; Sougrat, Rachid; Golinelli-Cohen, Marie-Pierre; Jackson, Catherine L.

2011-01-01

The Arf1 exchange factor GBF1 (Golgi Brefeldin A resistance factor 1) and its effector COPI are required for delivery of ATGL (adipose triglyceride lipase) to lipid droplets (LDs). Using yeast two hybrid, co-immunoprecipitation in mammalian cells and direct protein binding approaches, we report here that GBF1 and ATGL interact directly and in cells, through multiple contact sites on each protein. The C-terminal region of ATGL interacts with N-terminal domains of GBF1, including the catalytic Sec7 domain, but not with full-length GBF1 or its entire N-terminus. The N-terminal lipase domain of ATGL (called the patatin domain) interacts with two C-terminal domains of GBF1, HDS (Homology downstream of Sec7) 1 and HDS2. These two domains of GBF1 localize to lipid droplets when expressed alone in cells, but not to the Golgi, unlike the full-length GBF1 protein, which localizes to both. We suggest that interaction of GBF1 with ATGL may be involved in the membrane trafficking pathway mediated by GBF1, Arf1 and COPI that contributes to the localization of ATGL to lipid droplets.

Experiment K-6-03. Gravity and skeletal growth, part 1. Part 2: Morphology and histochemistry of bone cells and vasculature of the tibia; Part 3: Nuclear volume analysis of osteoblast histogenesis in periodontal ligament cells; Part 4: Intervertebral disc swelling pressure associated with microgravity

Science.gov (United States)

Holton, E.; Hargens, A.; Gonsalves, M.; Berretta, D.; Doty, S.; Roberts, W.; Garetto, L.; Kaplansky, A.; Durnova, G.; Gott, S.

1990-01-01

Bone area, bone electrophysiology, bone vascularity, osteoblast morphology, and osteoblast histogenesis were studied in rats associated with Cosmos 1887. The results suggest that the synchronous animals were the only group with a significantly larger bone area than the basal group, that the bone electrical potential was more negative in flight than in the synchronous rats, that the endosteal osteoblasts from flight rats had greater numbers of transitional Golgi vesicles but no difference in the large Golgi saccules or the alkaline phosphatase activity, that the perioteal vasculature in the shaft of flight rats often showed very dense intraluminal deposits with adjacent degenerating osteocytes as well as lipid accumulations within the lumen of the vessels and sometimes degeneration of the vascular wall (this change was not present in the metaphyseal region of flight animals), and that the progenitor cells decreased in flight rats while the preosteoblasts increased compared to controls. Many of the results suggest that the animals were beginning to recover from the effects of spaceflight during the two day interval between landing and euthanasia; flight effects, such as the vascular changes, did not appear to recover.

Luminal uptake and intracellular transport of insulin in renal proximal tubules

International Nuclear Information System (INIS)

Hellfritzsch, M.; Christensen, E.I.; Sonne, O.

1986-01-01

It is generally accepted that proteins taken up from the renal tubular fluid are transported into lysosomes in proximal tubule cells. Recently, however, it has been postulated that insulin in isolated perfused rat kidneys did not accumulate in lysosomes but to a certain degree in the Golgi region. The present study was undertaken to investigate the intracellular handling of biologically unaltered insulin in rat renal proximal tubule cells. Rats were prepared for in vivo micropuncture and either a colloidal gold insulin complex or insulin monoiodinated in the A-14 position ( 125 I-insulin) was microinfused into proximal tubules. After 5, 10, 25 or 60 min the tubules were fixed by microinfusion of glutaraldehyde and processed for electron microscopy or electron microscope autoradiography. A qualitative analysis of tubules infused with colloidal gold insulin or 125 I-insulin showed that insulin was taken up by endocytosis and transported to lysosomes, and a quantitative autoradiographic analysis of the 125 I-insulin microinfused tubules showed that the grain density after five min was significantly increased for endocytic vacuoles and for lysosomes. After 60 min the grain density was still significant over lysosomes. The accumulation of grains was non-significant over all other areas analyzed at any time. This study shows that insulin is taken up from the luminal side of the proximal tubule by endocytosis and transported to the lysosomes. There was no significant transport to the Golgi region

Mucopolysaccharides in the trabecular meshwork. Light and electron microscopic autoradiography

Energy Technology Data Exchange (ETDEWEB)

Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

1982-09-01

The localization of /sup 35/S-sulfate and /sup 3/H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of /sup 35/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid.

Mucopolysaccharides in the trabecular meshwork

International Nuclear Information System (INIS)

Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro

1982-01-01

The localization of 35 S-sulfate and 3 H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of 35 S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of 35 H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid. (author)

Ultra-estrutura de glândulas abdominais tegumentares em Oxaea flavescens (Hymenoptera, Andrenidae, Oxaeinae

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Guerino Adriane Cristina

2002-01-01

Full Text Available The sternal glands of the abdomen of Oxaea flavescens (Klug, 1807 consist of class III glandular cells around a reservoir constituted by branched folds of the intersegmental membrane of segments III, IV and V. The gland cells are rich in rough endoplasmic reticulum and produce a secretion with mucous aspect. The treatment with oxidated osmium and ruthenium red showed numerous Golgi regions in the cell and carbohydrates absorption from the haemolymph, respectively. The high degree of development of the glands suggests an important function to the species, although still unknown.

MR tomography in patients suffering from Parkinson's disease and Parkinson plus syndromes

International Nuclear Information System (INIS)

Hierholzer, J.; Schrag, A.; Cordes, M.; Sander, B.; Schelosky, L.; Harisch, C.; Venz, S.; Keske, U.; Maeurer, J.; Poewe, W.; Felix, R.

1996-01-01

To define characteristic MR-findings in patients with clinically typical extrapyramidal movement disorders. 15 patients with Parkinson's disease (PD), 9 with multisystem atrophy (MSA), and 6 with progressive supranuclear palsy (PSP) underwent MRI using a 1.5 T. Magnetom unit. Two investigators analysed the images with special regard to global and/or focal atrophy and to changes in signal intensity of the CNS in the consensus mode. Normal images of 10 subjects served as controls to patient's images. In all patients with PSP and MSA characteristic pathological findings on MRI were observed including regional changes within the extrapyramidal nuclei. In contrast all patients with PD had an unremarkable MRI study of the CNS. MRI enables us to define characteristic morphological changes of the brain in patients with extrapyramidal movement disorders. Early recognition of these findings avoids misdiagnoses in patients who are difficult to diagnose. (orig.) [de

Subcellular distribution of apolipoprotein E along the lipoprotein synthetic pathway of rat liver

International Nuclear Information System (INIS)

Cole, T.G.; Stockhausen, D.C.

1986-01-01

Apolipoprotein E (apoE) is synthesized by the liver and is secreted as a component of VLDL. To define the intracellular locations of apoE, liver from 10 nonfasted male rats were removed and subcellular organelles prepared by differential pelleting through sucrose gradients. Mass of apoE was measured by radioimmunoassay. Approximately 10% of total hepatic apoE was recovered in rough endoplasmic reticulum (RER), smooth endoplasmic reticulum (SER) and Golgi fractions. Concentrations of apoE (ng/mg protein) were: homogenate, 302 +/- 59; RER, 653 +/- 251; SER, 1250 +/- 471; Golgi, 11,044 +/- 4291. Total apoE content of each reaction (μg/organelle) was: homogenate (whole liver), 517 +/- 103; RER, 15 +/- 3; SER, 9 +/- 3; Golgi, 28 +/- 8. These data indicate that along the putative pathway of lipoprotein synthesis (RER->SER->Golgi), apoE concentration increases in each successive organelle and that flux of apoE is apparently most rapid through SER. Furthermore, the majority of apoE in the rat liver is apparently not directly associated with the lipoprotein synthetic pathway and may be associated with internalized lipoproteins or may be involved in non-lipoprotein related functions

Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis Neuroimagem no parkinsonismo: estudo com ressonância magnética e espectroscopia por ressonância como ferramentas no diagnóstico diferencial

Directory of Open Access Journals (Sweden)

Luiz Felipe Rocha Vasconcellos

2009-03-01

Full Text Available The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinson's disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type, and 10 individuals without any psychiatric or neurological disorders (controls. Clinical scales included Hoenh and Yahr, unified Parkinson's disease rating scale and mini mental status examination. The results showed that patients with Parkinson's disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism.O diagnóstico diferencial do parkinsonismo baseado em parâmetros clínicos pode ser difícil. Alguns exames complementares podem ser úteis, especialmente a ressonância magnética, um método não invasivo, de menor custo quando comparado a tomografia por emissão de pósitrons, proporcionando uma análise anatômica satisfatória. A ressonância por espectroscopia analisa o metabolismo cerebral, com resultados variáveis na literatura no estudo das síndromes parkinsonianas. Selecionamos 40 indivíduos para realização de ressonância magnética e espectroscopia, sendo 12 com doença de Parkinson, 11 com paralisia supranuclear progressiva, 7 com atrofia de múltiplos sistemas tipo parkinsoniana e 10 indivíduos sem manifesta

Comparison of regional brain atrophy and cognitive impairment between pure akinesia with gait freezing and Richardson's syndrome

Science.gov (United States)

Hong, Jin Yong; Yun, Hyuk Jin; Sunwoo, Mun Kyung; Ham, Jee Hyun; Lee, Jong-Min; Sohn, Young H.; Lee, Phil Hyu

2015-01-01

Pure akinesia with gait freezing (PAGF) is considered a clinical phenotype of progressive supranuclear palsy. The brain atrophy and cognitive deficits in PAGF are expected to be less prominent than in classical Richardson's syndrome (RS), but this hypothesis has not been explored yet. We reviewed the medical records of 28 patients with probable RS, 19 with PAGF, and 29 healthy controls, and compared cortical thickness, subcortical gray matter volume, and neuropsychological performance among the three groups. Patients with PAGF had thinner cortices in frontal, inferior parietal, and temporal areas compared with controls; however, areas of cortical thinning in PAGF patients were less extensive than those in RS patients. In PAGF patients, hippocampal, and thalamic volumes were also smaller than controls, whereas subcortical gray matter volumes in PAGF and RS patients were comparable. In a comparison of neuropsychological tests, PAGF patients had better cognitive performance in executive function, visual memory, and visuospatial function than RS patients had. These results demonstrate that cognitive impairment, cortical thinning, and subcortical gray matter atrophy in PAGF patients resemble to those in RS patients, though the severity of cortical thinning and cognitive dysfunction is milder. Our results suggest that, PAGF and RS may share same pathology but that it appears to affect a smaller proportion of the cortex in PAGF. PMID:26483680

The monomeric GTPase RabA2 is required for progression and maintenance of membrane integrity of infection threads during root nodule symbiosis.

Science.gov (United States)

Dalla Via, Virginia; Traubenik, Soledad; Rivero, Claudio; Aguilar, O Mario; Zanetti, María Eugenia; Blanco, Flavio Antonio

2017-04-01

Progression of the infection canal that conducts rhizobia to the nodule primordium requires a functional Rab GTPase located in Golgi/trans-Golgi that also participate in root hair polar growth. Common bean (Phaseolus vulgaris) symbiotically associates with its partner Rhizobium etli, resulting in the formation of root nitrogen-fixing nodules. Compatible bacteria can reach cortical cells in a tightly regulated infection process, in which the specific recognition of signal molecules is a key step to select the symbiotic partner. In this work, we show that RabA2, a monomeric GTPase from common bean, is required for the progression of the infection canal, referred to as the infection thread (IT), toward the cortical cells. Expression of miss-regulated mutant variants of RabA2 resulted in an increased number of abortive infection events, including bursting of ITs and a reduction in the number of nodules. Nodules formed in these plants were small and contained infected cells with disrupted symbiosome membranes, indicating either early senescence of these cells or defects in the formation of the symbiosome membrane during bacterial release. RabA2 localized to mobile vesicles around the IT, but mutations that affect GTP hydrolysis or GTP/GDP exchange modified this localization. Colocalization of RabA2 with ArfA1 and a Golgi marker indicates that RabA2 localizes in Golgi stacks and the trans-Golgi network. Our results suggest that RabA2 is part of the vesicle transport events required to maintain the integrity of the membrane during IT progression.

Yeast Interacting Proteins Database: YNR051C, YER151C [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available that coregulates anterograde and retrograde transport between the endoplasmic reticulum and Golgi compartme...C UBP3 Ubiquitin-specific protease that interacts with Bre5p to co-regulate anterograde and retrograde...t coregulates anterograde and retrograde transport between the endoplasmic reticulum and Golgi compartments;...3 Prey description Ubiquitin-specific protease that interacts with Bre5p to co-regulate anterograde and retrograde

Regional development and regional policy

OpenAIRE

Šabić, Dejan; Vujadinović, Snežana

2017-01-01

Economic polarization is a process that is present at global, national and regional level. Economic activity is extremely spatially concentrated. Cities and developed regions use the agglomeration effect to attract labor and capital, thus achieving more favorable economic conditions than the agrarian region. Scientific research and European experiences over the past decades have contributed to the discrepancy among theorists about the causes and consequences of regional inequalities. Regional...

Polarized trafficking: the palmitoylation cycle distributes cytoplasmic proteins to distinct neuronal compartments.

Science.gov (United States)

Tortosa, Elena; Hoogenraad, Casper C

2018-02-01

In neurons, polarized cargo distribution occurs mainly between the soma and axonal and dendritic compartments, and requires coordinated regulation of cytoskeletal remodeling and membrane trafficking. The Golgi complex plays a critical role during neuronal polarization and secretory trafficking has been shown to differentially transport proteins to both axons and dendrites. Besides the Golgi protein sorting, recent data revealed that palmitoylation cycles are an efficient mechanism to localize cytoplasmic, non-transmembrane proteins to particular neuronal compartments, such as the newly formed axon. Palmitoylation allows substrate proteins to bind to and ride with Golgi-derived secretory vesicles to all neuronal compartments. By allowing cytoplasmic proteins to 'hitchhike' on transport carriers in a non-polarized fashion, compartmentalized depalmitoylation may act as a selective retention mechanism. Copyright © 2018 Elsevier Ltd. All rights reserved.

Compressed Baryonic Matter of Astrophysics

OpenAIRE

Guo, Yanjun; Xu, Renxin

2013-01-01

Baryonic matter in the core of a massive and evolved star is compressed significantly to form a supra-nuclear object, and compressed baryonic matter (CBM) is then produced after supernova. The state of cold matter at a few nuclear density is pedagogically reviewed, with significant attention paid to a possible quark-cluster state conjectured from an astrophysical point of view.

Comparison of regional brain atrophy and cognitive impairment between pure akinesia with gait freezing and Richardson’s syndrome

Directory of Open Access Journals (Sweden)

Jin Yong eHong

2015-09-01

Full Text Available Pure akinesia with gait freezing (PAGF is considered a clinical phenotype of progressive supranuclear palsy. The brain atrophy and cognitive deficits in PAGF are expected to be less prominent than in classical Richardson’s syndrome (RS, but this hypothesis has not been explored yet. We reviewed the medical records of 28 patients with probable RS, 19 with PAGF, and 29 healthy controls, and compared cortical thickness, subcortical grey matter volume, and neuropsychological performance among the three groups. Patients with PAGF had thinner cortices in frontal, inferior parietal, and temporal areas compared with controls; however, areas of cortical thinning in PAGF patients were less extensive than those in RS patients. In PAGF patients, hippocampal and thalamic volumes were also smaller than controls, whereas subcortical grey matter volumes in PAGF and RS patients were comparable. In a comparison of neuropsychological tests, PAGF patients had better cognitive performance in executive function, visual memory, and visuospatial function than RS patients had. These results demonstrate that cognitive impairment, cortical thinning, and subcortical grey matter atrophy in PAGF patients resemble to those in RS patients, though the severity of cortical thinning and cognitive dysfunction is milder. Our results suggest that PAGF and RS may share same pathology but that it appears to affect a smaller proportion of the cortex in PAGF.

A comparative technetium 99m hexamethylpropylene amine oxime SPET study in different types of dementia

Energy Technology Data Exchange (ETDEWEB)

Habert, M O; Piketty, M L; Askienazy, S [Centre Hospitalier Sainte-Anne, 75 - Paris (France). Dept. de Medecine Nucleaire; Spampinato, U; Mas, J L; Recondo, J de; Rondot, P [Centre Hospitalier Sainte-Anne, 75 - Paris (France). Dept. de Neurologie; Bourdel, M C [Centre Hospitalier Sainte-Anne, 75 - Paris (France). Dept. de Psychiatrie

1991-01-01

Regional cerebral perfusion was evaluated by single photon emission tomography (SPET) using technetium 99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) as a tracer, in 13 control subjects and 44 age-matched patients suffering from dementia of the Alzheimer's type (DAT, n=19) presumed Pick's disease (n=5), idiopathic Parkinson's disease with dementia (DPD, n=15) and progressive supranuclear palsy (PSP, n=5), HMPAO uptake was measured in the superior frontal, inferior frontal, parietal, temporal and occipital cortices, and the perfusion values were expressed as cortical/cerebellar activity ratios. As compared with controls, tracer uptake ratios in the DAT group were signficantly reduced over all cortical regions, with the largest defects in the parieto-temporal and superior frontal cortices. A marked hypoperfusion affecting the superior and inferior frontal cortices was found in Pick's diesease, whereas a mild but significant hypoperfusion was observed only in the superior frontal cortex of patients with PSP. In the DPD group, HMPAO uptake was significantly reduced in the parietal, temporal and occipital cortices, but not in the frontal cortex. These results show that DAT and DPD share the opposite anteroposterior HMPAO uptake defect as compared with the Pick's and PSP groups. (orig.).

In vivo intracellular pH measurements in tobacco and Arabidopsis reveal an unexpected pH gradient in the endomembrane system.

Science.gov (United States)

Martinière, Alexandre; Bassil, Elias; Jublanc, Elodie; Alcon, Carine; Reguera, Maria; Sentenac, Hervé; Blumwald, Eduardo; Paris, Nadine

2013-10-01

The pH homeostasis of endomembranes is essential for cellular functions. In order to provide direct pH measurements in the endomembrane system lumen, we targeted genetically encoded ratiometric pH sensors to the cytosol, the endoplasmic reticulum, and the trans-Golgi, or the compartments labeled by the vacuolar sorting receptor (VSR), which includes the trans-Golgi network and prevacuoles. Using noninvasive live-cell imaging to measure pH, we show that a gradual acidification from the endoplasmic reticulum to the lytic vacuole exists, in both tobacco (Nicotiana tabacum) epidermal (ΔpH -1.5) and Arabidopsis thaliana root cells (ΔpH -2.1). The average pH in VSR compartments was intermediate between that of the trans-Golgi and the vacuole. Combining pH measurements with in vivo colocalization experiments, we found that the trans-Golgi network had an acidic pH of 6.1, while the prevacuole and late prevacuole were both more alkaline, with pH of 6.6 and 7.1, respectively. We also showed that endosomal pH, and subsequently vacuolar trafficking of soluble proteins, requires both vacuolar-type H(+) ATPase-dependent acidification as well as proton efflux mediated at least by the activity of endosomal sodium/proton NHX-type antiporters.

deep-orange and carnation define distinct stages in late endosomal biogenesis in Drosophila melanogaster.

Science.gov (United States)

Sriram, V; Krishnan, K S; Mayor, Satyajit

2003-05-12

Endosomal degradation is severely impaired in primary hemocytes from larvae of eye color mutants of Drosophila. Using high resolution imaging and immunofluorescence microscopy in these cells, products of eye color genes, deep-orange (dor) and carnation (car), are localized to large multivesicular Rab7-positive late endosomes containing Golgi-derived enzymes. These structures mature into small sized Dor-negative, Car-positive structures, which subsequently fuse to form tubular lysosomes. Defective endosomal degradation in mutant alleles of dor results from a failure of Golgi-derived vesicles to fuse with morphologically arrested Rab7-positive large sized endosomes, which are, however, normally acidified and mature with wild-type kinetics. This locates the site of Dor function to fusion of Golgi-derived vesicles with the large Rab7-positive endocytic compartments. In contrast, endosomal degradation is not considerably affected in car1 mutant; fusion of Golgi-derived vesicles and maturation of large sized endosomes is normal. However, removal of Dor from small sized Car-positive endosomes is slowed, and subsequent fusion with tubular lysosomes is abolished. Overexpression of Dor in car1 mutant aggravates this defect, implicating Car in the removal of Dor from endosomes. This suggests that, in addition to an independent role in fusion with tubular lysosomes, the Sec1p homologue, Car, regulates Dor function.

[A case of hereditary sensory and autonomic neuropathy type 1E with frontal lobe dysfunction as an initial symptom].

Science.gov (United States)

Watanabe, Masashi; Matsumoto, Yushi; Okamoto, Kensho; Okuda, Bungo; Mizuta, Ikuko; Mizuno, Toshiki

2017-12-27

A 49-year-old man had developed gradually personality change, gait disturbance, and hearing loss for five years. On admission, he presented with frontal release signs, stuttering, vertical gaze palsy, sensorineural deafness, muscle rigidity, ataxia, and sensory disturbance with areflexia in the lower extremities. Brain MRI demonstrated atrophy in the cerebellum and midbrain tegmentum as well as cerebral atrophy, predominantly in the frontal lobe. He was tentatively diagnosed as progressive supranuclear palsy on the basis of clinical features and imagings. On nerve conduction study, no sensory nerve action potentials were elicited in the upper and lower extremities. Details of family history revealed a hereditary sensory neuropathy with autosomal dominant inheritance in his relatives. Because genetic analysis showed a rare missense mutation (c.1483T>C, p.Y495H) in DNA methyltransferase 1 gene, we diagnosed him as having hereditary sensory and autonomic neuropathy type 1E (HSAN1E). In addition, p.M232R mutation in prion protein gene was detected. It should be kept in mind that there are some patients with HSAN1E presenting with frontal lobe dysfunction as an initial symptom and with clinical features mimicking progressive supranuclear palsy.

Cytochemical and x-ray microanalysis studies of intracellular calcium pools in scale-bearing cells of the coccolithophorid emiliana huxleyi

International Nuclear Information System (INIS)

Wal, P. van der; Bruijn, W.C. de; Westbroek, P.

1985-01-01

Emiliania huxleyi is a coccolithophorid with a life cycle including a stage characterized by the occurrence of a scale-bearing cell type. The scales are composed of organic material and are produced in the cisternae of the Golgi apparatus. The present report deals with the ultrastructural calcium localization in scale-bearing cells using cation-precipitating agents. Cations were precipitated either with potassium carbonate, or potassium phosphate, and then with potassium pyroantimonate. The distribution of electron-opaque deposits was the same when visualized by all four techniques. The most extensive deposits occurred in the Golgi apparatus, the 'peripheral space' (a cellular compartment totally encompassing the protoplast), the multivesicular bodies, and the cell vacuole. X-ray microanalysis revealed that calcium was a constituent of the electron-opaque deposits. The uptake and transport of calcium, as universal functions of the Golgi apparatus, are discussed. (Author)

The Root Cause of Post-Traumatic and Developmental Stress Disorder

Science.gov (United States)

2014-10-01

PTSD BA11 PTSD BA11 (Pɘ.023) and correlated to HLA-DRB3 mushroom spine density Nissl staining on whole hemisphere sections from the frontal...techniques. Initial golgi analysis of prefrontal anatomy and stereological studies of the frontal cortex in Nissl sections are in progress. Major...cortex/hippocampus of PTSD, MDD and controls, with 5HTTLPR and other genetic variants as cofactors. Fig A. Golgi staining (left) in the mOFCTX has been

An imaging flow cytometry method to assess ricin trafficking in A549 human lung epithelial cells.

Science.gov (United States)

Jenner, Dominic; Chong, Damien; Walker, Nicola; Green, A Christopher

2018-02-01

The endocytosis and trafficking of ricin in mammalian cells is an important area of research for those producing ricin anti-toxins and other ricin therapeutics. Ricin trafficking is usually observed by fluorescence microscopy techniques. This gives good resolution and leads to a detailed understanding of the internal movement of ricin within cells. However, microscopy techniques are often hampered by complex analysis and quantification techniques, and the inability to look at ricin trafficking in large populations of cells. In these studies we have directly labelled ricin and assessed if its trafficking can be observed using Imaging Flow Cytometry (IFC) both to the cytoplasmic region of cells and specifically to the Golgi apparatus. Using IDEAS® data analysis software the specific fluorescence location of the ricin within the cells was analysed. Then, using cytoplasmic masking techniques to quantify the number of cells with endocytosed cytoplasmic ricin or cells with Golgi-associated ricin, kinetic endocytosis curves were generated. Here we present, to the authors' knowledge, the first example of using imaging flow cytometry for evaluating the subcellular transport of protein cargo, using the trafficking of ricin toxin in lung cells as a model. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Returning "Region" to World Regional Geography

Science.gov (United States)

Rees, Peter W.; Legates, Margaret

2013-01-01

World regional geography textbooks rarely focus on the process of region formation, despite frequent calls to reincorporate a regional approach to teaching global geography. An instructional strategy using problem-based learning in a small honors section of a large world regional geography course is described. Using a hypothetical scenario…

Clinical usefulness of dopamine transporter imaging

International Nuclear Information System (INIS)

Kim, Jong Min; Kim, Yu Kyeong; Kim, Sang Eun; Jeon, Beom S.

2007-01-01

Imaging of the dopamine transporter (DAT) provides a marker for the integrity of presynaptic nigrostriatal dopaminergic system. DAT density is reduced in Parkinson disease, multiple system atrophy, and progressive supranuclear palsy. In patients with suspicious parkinsonism, normal DAT imaging suggests an alternative diagnosis such as essential tremor, vascular parkinsonism, or drug-induced parkinsonism. DAT imaging is a useful tool to aid clinician's differential diagnosis in parkinsonism

Ultrastructure of the midgut endocrine cells in Melipona quadrifasciata anthidioides (Hymenoptera, Apidae

Directory of Open Access Journals (Sweden)

C. A. Neves

Full Text Available In this study we describe the ultrastructure of the endocrine cells observed in the midgut of M. quadrifasciata anthidioides. This bee has two types of endocrine cells, which are numerous on the posterior midgut region. Cells of the closed type are smaller and have irregular secretory granules with lower electrondensity than those of the open cell type. The open cell type has elongated mitochondria mainly on the basal area, where most of the secretory granules are also found. Besides the secretion granules and mitochondria, endocrine cells in this species have well-developed autophagic vacuoles and Golgi complex elements.

Hawaii Regional Sediment Management (RSM): Regional Sediment Budget for the West Maui Region

Science.gov (United States)

2016-06-01

ER D C/ CH L TR -1 6- 5 Regional Sediment Management (RSM) Program Hawaii Regional Sediment Management (RSM): Regional Sediment Budget...acwc.sdp.sirsi.net/client/default. Regional Sediment Management (RSM) Program ERDC/CHL TR-16-5 June 2016 Hawaii Regional Sediment Management...distribution is unlimited. Prepared for U.S. Army Corps of Engineers Washington, DC 20314-1000 Under Project 454632, “ Hawaii Regional Sediment Management

Human Papillomavirus 16 Infection Induces VAP-Dependent Endosomal Tubulation.

Science.gov (United States)

Siddiqa, Abida; Massimi, Paola; Pim, David; Broniarczyk, Justyna; Banks, Lawrence

2018-03-15

Human papillomavirus (HPV) infection involves complex interactions with the endocytic transport machinery, which ultimately facilitates the entry of the incoming viral genomes into the trans -Golgi network (TGN) and their subsequent nuclear entry during mitosis. The endosomal pathway is a highly dynamic intracellular transport system, which consists of vesicular compartments and tubular extensions, although it is currently unclear whether incoming viruses specifically alter the endocytic machinery. In this study, using MICAL-L1 as a marker for tubulating endosomes, we show that incoming HPV-16 virions induce a profound alteration in global levels of endocytic tubulation. In addition, we also show a critical requirement for the endoplasmic reticulum (ER)-anchored protein VAP in this process. VAP plays an essential role in actin nucleation and endosome-to-Golgi transport. Indeed, the loss of VAP results in a dramatic decrease in the level of endosomal tubulation induced by incoming HPV-16 virions. This is also accompanied by a marked reduction in virus infectivity. In VAP knockdown cells, we see that the defect in virus trafficking occurs after capsid disassembly but prior to localization at the trans -Golgi network, with the incoming virion-transduced DNA accumulating in Vps29/TGN46-positive hybrid vesicles. Taken together, these studies demonstrate that infection with HPV-16 virions induces marked alterations of endocytic transport pathways, some of which are VAP dependent and required for the endosome-to-Golgi transport of the incoming viral L2/DNA complex. IMPORTANCE Human papillomavirus infectious entry involves multiple interactions with the endocytic transport machinery. In this study, we show that incoming HPV-16 virions induce a dramatic increase in endocytic tubulation. This tubulation requires ER-associated VAP, which plays a critical role in ensuring the delivery of cargoes from the endocytic compartments to the trans -Golgi network. Indeed, the loss of

ASEAN : Extra-Regional Cooperation Triggers Regional Integration

NARCIS (Netherlands)

Krapohl, S.; Krapohl, S.

2017-01-01

This chapter contains two case studies of regional cooperation within Southeast Asia. The network analysis of ASEAN demonstrates that the region is dependent on extra-regional trade with the EU and the USA, but also with China and Japan. However, the region is not dominated by a single regional

The golgin GMAP-210 is required for efficient membrane trafficking in the early secretory pathway

OpenAIRE

Roboti, Peristera; Sato, Keisuke; Lowe, Martin

2015-01-01

Golgins are coiled-coil proteins that participate in membrane-tethering events at the Golgi complex. Golgin-mediated tethering is thought to be important for vesicular trafficking and Golgi organization. However, the degree to which individual golgins contribute to these processes is poorly defined, and it has been proposed that golgins act in a largely redundant manner. Previous studies on the golgin GMAP-210 (also known as TRIP11), which is mutated in the rare skeletal disorder achondrogene...

Phosphatidylinositol 4-kinases: Function, structure, and inhibition

International Nuclear Information System (INIS)

Boura, Evzen; Nencka, Radim

2015-01-01

The phosphatidylinositol 4-kinases (PI4Ks) synthesize phosphatidylinositol 4-phosphate (PI4P), a key member of the phosphoinositide family. PI4P defines the membranes of Golgi and trans-Golgi network (TGN) and regulates trafficking to and from the Golgi. Humans have two type II PI4Ks (α and β) and two type III enzymes (α and β). Recently, the crystal structures were solved for both type II and type III kinase revealing atomic details of their function. Importantly, the type III PI4Ks are hijacked by +RNA viruses to create so-called membranous web, an extensively phosphorylated and modified membrane system dedicated to their replication. Therefore, selective and potent inhibitors of PI4Ks have been developed as potential antiviral agents. Here we focus on the structure and function of PI4Ks and their potential in human medicine

GLUT4 in cultured skeletal myotubes is segregated from the transferrin receptor and stored in vesicles associated with TGN

DEFF Research Database (Denmark)

Ralston, E; Ploug, Thorkil

1996-01-01

of the constitutive endosomal-lysosomal pathway. To address this question, we have investigated the localization of the endogenous GLUT4 in non-stimulated skeletal myotubes from the cell line C2, by immunofluorescence and immunoelectron microscopy. We have used a panel of antibodies to markers of the Golgi complex...... and in vesicles just beyond, i.e. in the structures that constitute the trans-Golgi network (TGN). In myotubes treated with brefeldin A, the immunofluorescence pattern of GLUT4 is modified, but it differs from both Golgi complex markers and TGN38. Instead, it resembles the pattern of the transferrin receptor...... to the GLUT4-containing tubulo-vesicular elements. In brefeldin A-treated cells, a network of tubules of approximately 70 nm diameter, studded with varicosities, stains for both GLUT4 and transferrin receptor, suggesting that brefeldin A has caused fusion of the transferrin receptor and GLUT4-containing...

Phosphatidylinositol 4-kinases: Function, structure, and inhibition

Energy Technology Data Exchange (ETDEWEB)

Boura, Evzen, E-mail: boura@uochb.cas.cz; Nencka, Radim, E-mail: nencka@uochb.cas.cz

2015-10-01

The phosphatidylinositol 4-kinases (PI4Ks) synthesize phosphatidylinositol 4-phosphate (PI4P), a key member of the phosphoinositide family. PI4P defines the membranes of Golgi and trans-Golgi network (TGN) and regulates trafficking to and from the Golgi. Humans have two type II PI4Ks (α and β) and two type III enzymes (α and β). Recently, the crystal structures were solved for both type II and type III kinase revealing atomic details of their function. Importantly, the type III PI4Ks are hijacked by +RNA viruses to create so-called membranous web, an extensively phosphorylated and modified membrane system dedicated to their replication. Therefore, selective and potent inhibitors of PI4Ks have been developed as potential antiviral agents. Here we focus on the structure and function of PI4Ks and their potential in human medicine.

Selective condensation drives partitioning and sequential secretion of cyst wall proteins in differentiating Giardia lamblia.

Directory of Open Access Journals (Sweden)

Christian Konrad

2010-04-01

Full Text Available Controlled secretion of a protective extracellular matrix is required for transmission of the infective stage of a large number of protozoan and metazoan parasites. Differentiating trophozoites of the highly minimized protozoan parasite Giardia lamblia secrete the proteinaceous portion of the cyst wall material (CWM consisting of three paralogous cyst wall proteins (CWP1-3 via organelles termed encystation-specific vesicles (ESVs. Phylogenetic and molecular data indicate that Diplomonads have lost a classical Golgi during reductive evolution. However, neogenesis of ESVs in encysting Giardia trophozoites transiently provides basic Golgi functions by accumulating presorted CWM exported from the ER for maturation. Based on this "minimal Golgi" hypothesis we predicted maturation of ESVs to a trans Golgi-like stage, which would manifest as a sorting event before regulated secretion of the CWM. Here we show that proteolytic processing of pro-CWP2 in maturing ESVs coincides with partitioning of CWM into two fractions, which are sorted and secreted sequentially with different kinetics. This novel sorting function leads to rapid assembly of a structurally defined outer cyst wall, followed by slow secretion of the remaining components. Using live cell microscopy we find direct evidence for condensed core formation in maturing ESVs. Core formation suggests that a mechanism controlled by phase transitions of the CWM from fluid to condensed and back likely drives CWM partitioning and makes sorting and sequential secretion possible. Blocking of CWP2 processing by a protease inhibitor leads to mis-sorting of a CWP2 reporter. Nevertheless, partitioning and sequential secretion of two portions of the CWM are unaffected in these cells. Although these cysts have a normal appearance they are not water resistant and therefore not infective. Our findings suggest that sequential assembly is a basic architectural principle of protective wall formation and requires

Characterization of yeast extracellular vesicles: evidence for the participation of different pathways of cellular traffic in vesicle biogenesis.

Directory of Open Access Journals (Sweden)

Débora L Oliveira

2010-06-01

Full Text Available Extracellular vesicles in yeast cells are involved in the molecular traffic across the cell wall. In yeast pathogens, these vesicles have been implicated in the transport of proteins, lipids, polysaccharide and pigments to the extracellular space. Cellular pathways required for the biogenesis of yeast extracellular vesicles are largely unknown.We characterized extracellular vesicle production in wild type (WT and mutant strains of the model yeast Saccharomyces cerevisiae using transmission electron microscopy in combination with light scattering analysis, lipid extraction and proteomics. WT cells and mutants with defective expression of Sec4p, a secretory vesicle-associated Rab GTPase essential for Golgi-derived exocytosis, or Snf7p, which is involved in multivesicular body (MVB formation, were analyzed in parallel. Bilayered vesicles with diameters at the 100-300 nm range were found in extracellular fractions from yeast cultures. Proteomic analysis of vesicular fractions from the cells aforementioned and additional mutants with defects in conventional secretion pathways (sec1-1, fusion of Golgi-derived exocytic vesicles with the plasma membrane; bos1-1, vesicle targeting to the Golgi complex or MVB functionality (vps23, late endosomal trafficking revealed a complex and interrelated protein collection. Semi-quantitative analysis of protein abundance revealed that mutations in both MVB- and Golgi-derived pathways affected the composition of yeast extracellular vesicles, but none abrogated vesicle production. Lipid analysis revealed that mutants with defects in Golgi-related components of the secretory pathway had slower vesicle release kinetics, as inferred from intracellular accumulation of sterols and reduced detection of these lipids in vesicle fractions in comparison with WT cells.Our results suggest that both conventional and unconventional pathways of secretion are required for biogenesis of extracellular vesicles, which demonstrate the

Promiscuous and specific phospholipid binding by domains in ZAC, a membrane-associated Arabidopsis protein with an ARF GAP zinc finger and a C2 domain

DEFF Research Database (Denmark)

Jensen, R B; Lykke-Andersen, K; Frandsen, G I

2000-01-01

domain are separated by a region without homology to other known proteins. Zac promoter/beta-glucuronidase reporter assays revealed highest expression levels in flowering tissue, rosettes and roots. ZAC protein was immuno-detected mainly in association with membranes and fractionated with Golgi...... and plasma membrane marker proteins. ZAC membrane association was confirmed in assays by a fusion between ZAC and the green fluorescence protein and prompted an analysis of the in vitro phospholipid-binding ability of ZAC. Phospholipid dot-blot and liposome-binding assays indicated that fusion proteins...... zinc finger motif, but proteins containing only the zinc finger domain (residues 1-105) did not bind PI-3-P. Recombinant ZAC possessed GTPase-activating activity on Arabidopsis ARF proteins. These data identify a novel PI-3-P-binding protein region and thereby provide evidence...

Dual pulse-chase microscopy reveals early divergence in the biosynthetic trafficking of the Na,K-ATPase and E-cadherin

Science.gov (United States)

Farr, Glen A.; Hull, Michael; Stoops, Emily H.; Bateson, Rosalie; Caplan, Michael J.

2015-01-01

Recent evidence indicates that newly synthesized membrane proteins that share the same distributions in the plasma membranes of polarized epithelial cells can pursue a variety of distinct trafficking routes as they travel from the Golgi complex to their common destination at the cell surface. In most polarized epithelial cells, both the Na,K-ATPase and E-cadherin are localized to the basolateral domains of the plasma membrane. To examine the itineraries pursued by newly synthesized Na,K-ATPase and E-cadherin in polarized MDCK epithelial cells, we used the SNAP and CLIP labeling systems to fluorescently tag temporally defined cohorts of these proteins and observe their behaviors simultaneously as they traverse the secretory pathway. These experiments reveal that E-cadherin is delivered to the cell surface substantially faster than is the Na,K-ATPase. Furthermore, the surface delivery of newly synthesized E-cadherin to the plasma membrane was not prevented by the 19°C temperature block that inhibits the trafficking of most proteins, including the Na,K-ATPase, out of the trans-Golgi network. Consistent with these distinct behaviors, populations of newly synthesized E-cadherin and Na,K-ATPase become separated from one another within the trans-Golgi network, suggesting that they are sorted into different carrier vesicles that mediate their post-Golgi trafficking. PMID:26424804

Structure and formation of egg membranes in Aedes aegypti. (L. ) (Diptera:Culicidae)

Energy Technology Data Exchange (ETDEWEB)

Mathew, G; Rai, K S

1975-01-01

An ultrastructural study of mosquito ovarioles reveals that both the vitelline membrane and the endochorion are secreted by the follicular epithelium. The presecretory phase is characterized by the hypertrophy of endoplasmic reticulum and Golgi complex in the follicle cells. Synthesis of vitelline membrane precursors begins immediately after yolk protein uptake by micropinocytosis. Secretory droplets are budded off Golgi cisternae and released into the follicle cell--oocyte interface by exocytosis. The vitelline membrane first appears as dense plaques which eventually fuse to form a single homogeneous layer. Two types of secretory material are identified in the follicle cells prior to the formation of the endochorion. Golgi cisternae bud off small droplets similar in size and appearance to the precursors of the vitelline membrane. These migrate to the apical surface and accumulate between surface folds in the plasma membrane. The second type is a fibrous material formed in endoplasmic reticulum. When fully secreted, the endochorion is a 2-layered structure. The lower layer is comprised of pillar-like structures alternating with fibrous mesh-like areas. The pillars are formed by the coalescence of droplets released from Golgi, while the mesh-like areas presumably arise from the fibrous material. The outer layer is also fibrous. The follicle cells degenerate once the endochorion is laid down. endochorion is laid down.

Regional planning without means - search for regional leadership

DEFF Research Database (Denmark)

Groth, Niels Boje; Fertner, Christian

and stakeholders, not least due to its polycentric urban structure with several medium-sized towns. Besides the regional authority and the regions 22 municipalities, sub-regional collaboration is gaining momentum. Furthermore, different fora, councils and associations are engaging in regional issues. However......, collaboration is often focused on specific sectors or sub-regions, while the joint development of the region is left behind. The regional authority has changed its focus from planning to the provision of knowledge, suitable to kick-off joint action with regional stakeholders, while municipalities keep focus...... on their own territories, eventually in the context of one of the new sub-regional collaborations. Based on an empirical analysis of the regional interplay in Southern Denmark and results from the ESPON ReSSI project, we go through these new settings of regional collaboration in the search for new forms...

A histidine-rich linker region in peptidylglycine α-amidating monooxygenase has the properties of a pH sensor.

Science.gov (United States)

Vishwanatha, Kurutihalli; Bäck, Nils; Mains, Richard E; Eipper, Betty A

2014-05-02

Decreasing luminal pH is thought to play a role in the entry of newly synthesized and endocytosed membrane proteins into secretory granules. The two catalytic domains of peptidylglycine α-amidating monooxygenase (PAM), a type I integral membrane protein, catalyze the sequential reactions that convert peptidyl-Gly substrates into amidated products. We explored the hypothesis that a conserved His-rich cluster (His-Gly-His-His) in the linker region connecting its two catalytic domains senses pH and affects PAM trafficking by mutating these His residues to Ala (Ala-Gly-Ala-Ala; H3A). Purified recombinant wild-type and H3A linker peptides were examined using circular dichroism and tryptophan fluorescence; mutation of the His cluster largely eliminated its pH sensitivity. An enzymatically active PAM protein with the same mutations (PAM-1/H3A) was expressed in HEK293 cells and AtT-20 corticotrope tumor cells. Metabolic labeling followed by immunoprecipitation revealed more rapid loss of newly synthesized PAM-1/H3A than PAM-1; although release of newly synthesized monofunctional PHM/H3A was increased, release of soluble bifunctional PAM/H3A, a product of the endocytic pathway, was decreased. Surface biotinylation revealed rapid loss of PAM-1/H3A, with no detectable return of the mutant protein to secretory granules. Consistent with its altered endocytic trafficking, little PAM-1/H3A was subjected to regulated intramembrane proteolysis followed by release of a small nuclear-targeted cytosolic fragment. AtT-20 cells expressing PAM-1/H3A adopted the morphology of wild-type AtT-20 cells; secretory products no longer accumulated in the trans-Golgi network and secretory granule exocytosis was more responsive to secretagogue.

Purposeless Groaning in Parkinson’s Disease

Directory of Open Access Journals (Sweden)

Shen-Yang Lim

2018-05-01

Full Text Available Purposeless groaning has been reported in advanced progressive supranuclear palsy. We present a case of purposeless groaning occurring as a primary complaint in a patient with advanced Parkinson’s disease. Purposeless groaning is thought to be a manifestation of disinhibition and perseveration due to frontal-subcortical dysfunction. Proper recognition of this phenomenon will help clinicians to avoid unnecessary investigations and treatment (e.g., prescription of opioid medications.

9.4 T MR microscopy of the substantia nigra with pathological validation in controls and disease

Directory of Open Access Journals (Sweden)

LA Massey

2017-01-01

Conclusions: We present a histologically validated anatomical description of the substantia nigra on high field spin-echo high resolution magnetic resonance images and were able to delineate all five nigrosomes. In accordance with the pathological literature we did not observe changes in the nigrosome structure as manifest by volume or signal characteristics within the substantia nigra in Parkinson's disease whereas in progressive supranuclear palsy there was microarchitectural destruction.

Herpes simplex virus 1 induces de novo phospholipid synthesis

Energy Technology Data Exchange (ETDEWEB)

Sutter, Esther [Electron Microscopy, Institute of Veterinary Anatomy, University of Zuerich (Switzerland); Oliveira, Anna Paula de; Tobler, Kurt [Electron microscopy, Institute of Virology, University of Zuerich (Switzerland); Schraner, Elisabeth M. [Electron Microscopy, Institute of Veterinary Anatomy, University of Zuerich (Switzerland); Sonda, Sabrina [Institute of Parasitology, University of Zuerich (Switzerland); Kaech, Andres [Center for Microscopy and Image Analysis, University of Zuerich (Switzerland); Lucas, Miriam S. [Electron Microscopy ETH Zuerich (EMEZ), Swiss Federal Institute of Technology, Zuerich (Switzerland); Ackermann, Mathias [Electron microscopy, Institute of Virology, University of Zuerich (Switzerland); Wild, Peter, E-mail: pewild@access.uzh.ch [Electron Microscopy, Institute of Veterinary Anatomy, University of Zuerich (Switzerland)

2012-08-01

Herpes simplex virus type 1 capsids bud at nuclear membranes and Golgi membranes acquiring an envelope composed of phospholipids. Hence, we measured incorporation of phospholipid precursors into these membranes, and quantified changes in size of cellular compartments by morphometric analysis. Incorporation of [{sup 3}H]-choline into both nuclear and cytoplasmic membranes was significantly enhanced upon infection. [{sup 3}H]-choline was also part of isolated virions even grown in the presence of brefeldin A. Nuclei expanded early in infection. The Golgi complex and vacuoles increased substantially whereas the endoplasmic reticulum enlarged only temporarily. The data suggest that HSV-1 stimulates phospholipid synthesis, and that de novo synthesized phospholipids are inserted into nuclear and cytoplasmic membranes to i) maintain membrane integrity in the course of nuclear and cellular expansion, ii) to supply membrane constituents for envelopment of capsids by budding at nuclear membranes and Golgi membranes, and iii) to provide membranes for formation of transport vacuoles.

Three-dimensional structure of Rubella virus factories

International Nuclear Information System (INIS)

Fontana, Juan; Lopez-Iglesias, Carmen; Tzeng, Wen-Ping; Frey, Teryl K.; Fernandez, Jose J.; Risco, Cristina

2010-01-01

Viral factories are complex structures in the infected cell where viruses compartmentalize their life cycle. Rubella virus (RUBV) assembles factories by recruitment of rough endoplasmic reticulum (RER), mitochondria and Golgi around modified lysosomes known as cytopathic vacuoles or CPVs. These organelles contain active replication complexes that transfer replicated RNA to assembly sites in Golgi membranes. We have studied the structure of RUBV factory in three dimensions by electron tomography and freeze-fracture. CPVs contain stacked membranes, rigid sheets, small vesicles and large vacuoles. These membranes are interconnected and in communication with the endocytic pathway since they incorporate endocytosed BSA-gold. RER and CPVs are coupled through protein bridges and closely apposed membranes. Golgi vesicles attach to the CPVs but no tight contacts with mitochondria were detected. Immunogold labelling confirmed that the mitochondrial protein p32 is an abundant component around and inside CPVs where it could play important roles in factory activities.

Mutational analysis of the yeast TRAPP subunit Trs20p identifies roles in endocytic recycling and sporulation.

Directory of Open Access Journals (Sweden)

Hichem Mahfouz

Full Text Available Trs20p is a subunit of the evolutionarily conserved TRAPP (TRAnsport Protein Particle complex that mediates various aspects of membrane trafficking. Three TRAPP complexes have been identified in yeast with roles in ER-to-Golgi trafficking, post-Golgi and endosomal-to-Golgi transport and in autophagy. The role of Trs20p, which is essential for viability and a component of all three complexes, and how it might function within each TRAPP complex, has not been clarified to date. To begin to address the role of Trs20p we generated different mutants by random mutagenesis but, surprisingly, no defects were observed in diverse anterograde transport pathways or general secretion in Trs20 temperature-sensitive mutants. Instead, mutation of Trs20 led to defects in endocytic recycling and a block in sporulation/meiosis. The phenotypes of different mutants appear to be separable suggesting that the mutations affect the function of Trs20 in different TRAPP complexes.

Two Novel Rab2 Interactors Regulate Dense-core Vesicle Maturation

Science.gov (United States)

Ailion, Michael; Hannemann, Mandy; Dalton, Susan; Pappas, Andrea; Watanabe, Shigeki; Hegermann, Jan; Liu, Qiang; Han, Hsiao-Fen; Gu, Mingyu; Goulding, Morgan Q.; Sasidharan, Nikhil; Schuske, Kim; Hullett, Patrick; Eimer, Stefan; Jorgensen, Erik M.

2014-01-01

Summary Peptide neuromodulators are released from a unique organelle: the dense-core vesicle. Dense-core vesicles are generated at the trans-Golgi, and then sort cargo during maturation before being secreted. To identify proteins that act in this pathway, we performed a genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We identified two conserved Rab2-binding proteins: RUND-1, a RUN domain protein, and CCCP-1, a coiled-coil protein. RUND-1 and CCCP-1 colocalize with RAB-2 at the Golgi, and rab-2, rund-1 and cccp-1 mutants have similar defects in sorting soluble and transmembrane dense-core vesicle cargos. RUND-1 also interacts with the Rab2 GAP protein TBC-8 and the BAR domain protein RIC-19, a RAB-2 effector. In summary, a new pathway of conserved proteins controls the maturation of dense-core vesicles at the trans-Golgi network. PMID:24698274

System-wide organization of actin cytoskeleton determines organelle transport in hypocotyl plant cells

Science.gov (United States)

Nowak, Jacqueline; Ivakov, Alexander; Somssich, Marc; Persson, Staffan; Nikoloski, Zoran

2017-01-01

The actin cytoskeleton is an essential intracellular filamentous structure that underpins cellular transport and cytoplasmic streaming in plant cells. However, the system-level properties of actin-based cellular trafficking remain tenuous, largely due to the inability to quantify key features of the actin cytoskeleton. Here, we developed an automated image-based, network-driven framework to accurately segment and quantify actin cytoskeletal structures and Golgi transport. We show that the actin cytoskeleton in both growing and elongated hypocotyl cells has structural properties facilitating efficient transport. Our findings suggest that the erratic movement of Golgi is a stable cellular phenomenon that might optimize distribution efficiency of cell material. Moreover, we demonstrate that Golgi transport in hypocotyl cells can be accurately predicted from the actin network topology alone. Thus, our framework provides quantitative evidence for system-wide coordination of cellular transport in plant cells and can be readily applied to investigate cytoskeletal organization and transport in other organisms. PMID:28655850

Inhibition of the Secretory pathway by Foot-and-Mouth disease virus 2BC protein is reproduced by co-expression of 2B with 2C, and the site of inhibition is determined by the subcellular location of 2C

DEFF Research Database (Denmark)

Moffat, Katy; Knox, Caroline; Howell, Gareth

2007-01-01

immune responses in vivo. Foot-and-mouth disease virus (FMDV), another picornavirus, can cause persistent infection of ruminants, suggesting it too may inhibit immune responses. Endoplasmic reticulum (ER)-to-Golgi apparatus transport of proteins is blocked by the FMDV 2BC protein. The observation that 2...... blocked in FMDV-infected cells. The block could be reconstituted by coexpression of 2B and 2C, showing that processing of 2BC did not compromise the ability of FMDV to slow secretion. Under these conditions, 2C was located to the Golgi apparatus, and the block in transport also occurred in the Golgi...... apparatus. Interestingly, the block in transport could be redirected to the ER when 2B was coexpressed with a 2C protein fused to an ER retention element. Thus, for FMDV a block in secretion is dependent on both 2B and 2C, with the latter determining the site of the block....

A pH-Regulated Quality Control Cycle for Surveillance of Secretory Protein Assembly

Science.gov (United States)

Vavassori, Stefano; Cortini, Margherita; Masui, Shoji; Sannino, Sara; Anelli, Tiziana; Caserta, Imma R.; Fagioli, Claudio; Mossuto, Maria F.; Fornili, Arianna; van Anken, Eelco; Degano, Massimo; Inaba, Kenji; Sitia, Roberto

2013-01-01

Summary To warrant the quality of the secretory proteome, stringent control systems operate at the endoplasmic reticulum (ER)-Golgi interface, preventing the release of nonnative products. Incompletely assembled oligomeric proteins that are deemed correctly folded must rely on additional quality control mechanisms dedicated to proper assembly. Here we unveil how ERp44 cycles between cisGolgi and ER in a pH-regulated manner, patrolling assembly of disulfide-linked oligomers such as IgM and adiponectin. At neutral, ER-equivalent pH, the ERp44 carboxy-terminal tail occludes the substrate-binding site. At the lower pH of the cisGolgi, conformational rearrangements of this peptide, likely involving protonation of ERp44’s active cysteine, simultaneously unmask the substrate binding site and −RDEL motif, allowing capture of orphan secretory protein subunits and ER retrieval via KDEL receptors. The ERp44 assembly control cycle couples secretion fidelity and efficiency downstream of the calnexin/calreticulin and BiP-dependent quality control cycles. PMID:23685074

Brefeldin A inhibits pestivirus release from infected cells, without affecting its assembly and infectivity

International Nuclear Information System (INIS)

Macovei, Alina; Zitzmann, Nicole; Lazar, Catalin; Dwek, Raymond A.; Branza-Nichita, Norica

2006-01-01

The enveloped bovine viral diarrhea virus (BVDV) is a member of the Pestivirus genus within the Flaviviridae family. While considerable information has been gathered on virus entry into the host cell, genome structure and protein function, little is known about pestivirus morphogenesis and release from cells. Here, we analyzed the intracellular localization, N-glycan processing and secretion of BVDV using brefeldin A (BFA), which blocks protein export from the endoplasmic reticulum (ER) and causes disruption of the Golgi complex with subsequent fusion of its cis and medial cisternae with the ER. BFA treatment of infected cells resulted in complete inhibition of BVDV secretion and increased co-localization of the envelope glycoproteins with the cis-Golgi marker GM 130. Processing of the N-linked glycans was affected by BFA, however, virus assembly was not perturbed and intracellular virions were fully infectious, suggesting that trafficking beyond the cis-Golgi is not a prerequisite for pestivirus infectivity

Brefeldin A inhibits pestivirus release from infected cells, without affecting its assembly and infectivity.

Science.gov (United States)

Macovei, Alina; Zitzmann, Nicole; Lazar, Catalin; Dwek, Raymond A; Branza-Nichita, Norica

2006-08-04

The enveloped bovine viral diarrhea virus (BVDV) is a member of the Pestivirus genus within the Flaviviridae family. While considerable information has been gathered on virus entry into the host cell, genome structure and protein function, little is known about pestivirus morphogenesis and release from cells. Here, we analyzed the intracellular localization, N-glycan processing and secretion of BVDV using brefeldin A (BFA), which blocks protein export from the endoplasmic reticulum (ER) and causes disruption of the Golgi complex with subsequent fusion of its cis and medial cisternae with the ER. BFA treatment of infected cells resulted in complete inhibition of BVDV secretion and increased co-localization of the envelope glycoproteins with the cis-Golgi marker GM 130. Processing of the N-linked glycans was affected by BFA, however, virus assembly was not perturbed and intracellular virions were fully infectious, suggesting that trafficking beyond the cis-Golgi is not a prerequisite for pestivirus infectivity.

Record linkage between hospital discharges and mortality registries for motor neuron disease case ascertainment for the Spanish National Rare Diseases Registry.

Science.gov (United States)

Ruiz, Elena; Ramalle-Gómara, Enrique; Quiñones, Carmen

2014-06-01

Our objective was to analyse the coverage of hospital discharge data and the mortality registry (MR) of La Rioja to ascertain motor neuron disease (MND) cases to be included in the Spanish National Rare Diseases Registry. MND cases that occurred in La Rioja during the period 1996-2011 were selected from hospital discharge data and the MR by means of the International Classification of Diseases. Review of the medical histories was carried out to confirm the causes of death reported. Characteristics of the population with MND were analysed. A total of 133 patients with MND were detected in La Rioja during the period 1996-2011; 30.1% were only recorded in the hospital discharges data, 12.0% only in the MR, and 57.9% were recorded by both databases. Medical records revealed a miscoding of patients who had been diagnosed with progressive supranuclear palsy but were recorded in the MR with an MND code. In conclusion, the hospital discharges data and the MR appear to be complementary and are valuable databases for the Spanish National Rare Diseases Registry when MNDs are properly codified. Nevertheless, it would be advisable to corroborate the validity of the MR as data source since the miscoding of progressive supranuclear palsy has been corrected.

PSP-CBS with Dopamine Deficiency in a Female with a FMR1 Premutation.

Science.gov (United States)

Paucar, Martin; Beniaminov, Stanislav; Paslawski, Wojciech; Svenningsson, Per

2016-10-01

Premutations in the fragile X mental retardation 1 (FMR1) gene cause fragile X-associated tremor/ataxia syndrome (FXTAS) and FMR1-related primary ovarian insufficiency (POI). Female FMR1 premutation carriers rarely develop motor features. Dual pathology is an emerging phenomenon among FMR1 premutation carriers. Here, we describe a family affected by FMR1-related disorders in which the female index case has developed a rapidly progressive and disabling syndrome of atypical parkinsonism. This syndrome consists of early onset postural instability, echolalia, dystonia, and varying types of apraxia like early onset orobuccal apraxia and oculomotor apraxia. She has also developed supranuclear gaze palsy, increased latency of saccade initiation, and slow saccades. These features are compatible with progressive supranuclear palsy (PSP) of a corticobasal syndrome (CBS) variant. Imaging displays a marked reduction of presynaptic dopaminergic uptake and cerebrospinal fluid analysis showed reduced dopamine metabolism; however, the patient is unresponsive to levodopa. Midbrain atrophy ("hummingbird sign") and mild cerebellar atrophy were found on brain MRI. Her father was affected by a typical FXTAS presentation but also displayed dopamine deficiency along with the hummingbird sign. The mechanisms by which FMR1 premutations predispose to atypical parkinsonism and dopamine deficiency await further elucidation.

Immunomicroscopic localization of aminopeptidase N in the pig enterocyte. Implications for the route of intracellular transport

DEFF Research Database (Denmark)

Hansen, Gert Helge; Sjöström, H; Norén, Ove

1987-01-01

The subcellular localization of aminopeptidase N (EC 3.4.11.2) in the pig enterocyte was investigated by immunofluorescence and immunoelectron microscopy (immunogold staining). By indirect immunofluorescence on either frozen or paraffin-embedded sections, a very intense staining in the microvillar....... Labelling was demonstrated in the Golgi apparatus and in a minor fraction of the intracellular smooth vesicles positioned between the Golgi apparatus and the microvillar membrane. These observations are compatible with the view that newly synthesized aminopeptidase N is delivered directly to the microvillar...

Osh4p is needed to reduce the level of phosphatidylinositol-4-phosphate on secretory vesicles as they mature

OpenAIRE

Ling, Yading; Hayano, Scott; Novick, Peter

2014-01-01

Phosphatidylinositol-4-phosphate (PI4P) is produced on both the Golgi and the plasma membrane. Despite extensive vesicular traffic between these compartments, genetic analysis suggests that the two pools of PI4P do not efficiently mix with one another. Several lines of evidence indicate that the PI4P produced on the Golgi is normally incorporated into secretory vesicles, but the fate of that pool has been unclear. We show here that in yeast the oxysterol-binding proteins Osh1?Osh7 are collect...

Common inversion polymorphism at 17q21.31 affects expression of multiple genes in tissue-specific manner.

Science.gov (United States)

de Jong, Simone; Chepelev, Iouri; Janson, Esther; Strengman, Eric; van den Berg, Leonard H; Veldink, Jan H; Ophoff, Roel A

2012-09-06

Chromosome 17q21.31 contains a common inversion polymorphism of approximately 900 kb in populations with European ancestry. Two divergent MAPT haplotypes, H1 and H2 are described with distinct linkage disequilibrium patterns across the region reflecting the inversion status at this locus. The MAPT H1 haplotype has been associated with progressive supranuclear palsy, corticobasal degeneration, Parkinson's disease and Alzheimer's disease, while the H2 is linked to recurrent deletion events associated with the 17q21.31 microdeletion syndrome, a disease characterized by developmental delay and learning disability. In this study, we investigate the effect of the inversion on the expression of genes in the 17q21.31 region. We find the expression of several genes in and at the borders of the inversion to be affected; specific either to whole blood or different regions of the human brain. The H1 haplotype was found to be associated with an increased expression of LRRC37A4, PLEKH1M and MAPT. In contrast, a decreased expression of MGC57346, LRRC37A and CRHR1 was associated with H1. Studies thus far have focused on the expression of MAPT in the inversion region. However, our results show that the inversion status affects expression of other genes in the 17q21.31 region as well. Given the link between the inversion status and different neurological diseases, these genes may also be involved in disease pathology, possibly in a tissue-specific manner.

TBC-8, a putative RAB-2 GAP, regulates dense core vesicle maturation in Caenorhabditis elegans.

Science.gov (United States)

Hannemann, Mandy; Sasidharan, Nikhil; Hegermann, Jan; Kutscher, Lena M; Koenig, Sabine; Eimer, Stefan

2012-01-01

Dense core vesicles (DCVs) are thought to be generated at the late Golgi apparatus as immature DCVs, which subsequently undergo a maturation process through clathrin-mediated membrane remodeling events. This maturation process is required for efficient processing of neuropeptides within DCVs and for removal of factors that would otherwise interfere with DCV release. Previously, we have shown that the GTPase, RAB-2, and its effector, RIC-19, are involved in DCV maturation in Caenorhabditis elegans motoneurons. In rab-2 mutants, specific cargo is lost from maturing DCVs and missorted into the endosomal/lysosomal degradation route. Cargo loss could be prevented by blocking endosomal delivery. This suggests that RAB-2 is involved in retention of DCV components during the sorting process at the Golgi-endosomal interface. To understand how RAB-2 activity is regulated at the Golgi, we screened for RAB-2-specific GTPase activating proteins (GAPs). We identified a potential RAB-2 GAP, TBC-8, which is exclusively expressed in neurons and which, when depleted, shows similar DCV maturation defects as rab-2 mutants. We could demonstrate that RAB-2 binds to its putative GAP, TBC-8. Interestingly, TBC-8 also binds to the RAB-2 effector, RIC-19. This interaction appears to be conserved as TBC-8 also interacted with the human ortholog of RIC-19, ICA69. Therefore, we propose that a dynamic ON/OFF cycling of RAB-2 at the Golgi induced by the GAP/effector complex is required for proper DCV maturation.

Metabolic topography of Parkinsonism

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Seung [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2007-04-15

Parkinson's disease is one of the most frequent neurodegenerative diseases, which mainly affects the elderly. Parkinson's disease is often difficult to differentiate from atypical parkinson disorder such as progressive supranuclear palsy, multiple system atrophy, dementia with Lewy body, and corticobasal ganglionic degeneration, based on the clinical findings because of the similarity of phenotypes and lack of diagnostic markers. The accurate diagnosis of Parkinson's disease and atypical Parkinson disorders is not only important for deciding on treatment regimens and providing prognosis, but also it is critical for studies designed to investigate etiology and pathogenesis of parkinsonism and to develop new therapeutic strategies. Although degeneration of the nigrostriatal dopamine system results in marked loss of striatal dopamine content in most of the diseases causing parkinsonism, pathologic studies revealed different topographies of the neuronal cell loss in Parkinsonism. Since the regional cerebral glucose metabolism is a marker of integrated local synaptic activity and as such is sensitive to both direct neuronal/synaptic damage and secondary functional disruption at synapses distant from the primary site of pathology, and assessment of the regional cerebral glucose metabolism with F-18 FDG PET is useful in the differential diagnosis of parkinsonism and evaluating the pathophysiology of Parkinsonism.

Metabolic topography of Parkinsonism

International Nuclear Information System (INIS)

Kim, Jae Seung

2007-01-01

Parkinson's disease is one of the most frequent neurodegenerative diseases, which mainly affects the elderly. Parkinson's disease is often difficult to differentiate from atypical parkinson disorder such as progressive supranuclear palsy, multiple system atrophy, dementia with Lewy body, and corticobasal ganglionic degeneration, based on the clinical findings because of the similarity of phenotypes and lack of diagnostic markers. The accurate diagnosis of Parkinson's disease and atypical Parkinson disorders is not only important for deciding on treatment regimens and providing prognosis, but also it is critical for studies designed to investigate etiology and pathogenesis of parkinsonism and to develop new therapeutic strategies. Although degeneration of the nigrostriatal dopamine system results in marked loss of striatal dopamine content in most of the diseases causing parkinsonism, pathologic studies revealed different topographies of the neuronal cell loss in Parkinsonism. Since the regional cerebral glucose metabolism is a marker of integrated local synaptic activity and as such is sensitive to both direct neuronal/synaptic damage and secondary functional disruption at synapses distant from the primary site of pathology, and assessment of the regional cerebral glucose metabolism with F-18 FDG PET is useful in the differential diagnosis of parkinsonism and evaluating the pathophysiology of Parkinsonism

A comparative technetium 99m hexamethylpropylene amine oxime SPET study in different types of dementia

Energy Technology Data Exchange (ETDEWEB)

Habert, M.O.; Piketty, M.L.; Askienazy, S. (Centre Hospitalier Sainte-Anne, 75 - Paris (France). Dept. de Medecine Nucleaire); Spampinato, U.; Mas, J.L.; Recondo, J. de; Rondot, P. (Centre Hospitalier Sainte-Anne, 75 - Paris (France). Dept. de Neurologie); Bourdel, M.C. (Centre Hospitalier Sainte-Anne, 75 - Paris (France). Dept. de Psychiatrie)

1991-01-01

Regional cerebral perfusion was evaluated by single photon emission tomography (SPET) using technetium 99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) as a tracer, in 13 control subjects and 44 age-matched patients suffering from dementia of the Alzheimer's type (DAT, n=19) presumed Pick's disease (n=5), idiopathic Parkinson's disease with dementia (DPD, n=15) and progressive supranuclear palsy (PSP, n=5), HMPAO uptake was measured in the superior frontal, inferior frontal, parietal, temporal and occipital cortices, and the perfusion values were expressed as cortical/cerebellar activity ratios. As compared with controls, tracer uptake ratios in the DAT group were signficantly reduced over all cortical regions, with the largest defects in the parieto-temporal and superior frontal cortices. A marked hypoperfusion affecting the superior and inferior frontal cortices was found in Pick's diesease, whereas a mild but significant hypoperfusion was observed only in the superior frontal cortex of patients with PSP. In the DPD group, HMPAO uptake was significantly reduced in the parietal, temporal and occipital cortices, but not in the frontal cortex. These results show that DAT and DPD share the opposite anteroposterior HMPAO uptake defect as compared with the Pick's and PSP groups. (orig.).

Active region structures in the transition region and corona

International Nuclear Information System (INIS)

Webb, D.F.

1981-01-01

Observational aspects of the transition region and coronal structures of the solar active region are reviewed with an emphasis on imaging of the plasma loops which act as tracers of the magnetic flux loops. The study of the basic structure of an active region is discussed in terms of the morphological and thermal classifications of active region loops, including umbral structures, and observational knowledge of the thermal structure of loops is considered in relation to scaling laws, emission measures and the structures of individual loops. The temporal evolution of active region loop structures is reviewed with emphasis on ephemeral regions and the emergence of active regions. Planned future spaceborne observations of active region loop structures in the EUV and soft X-ray regions are also indicated

Pep3p/Pep5p complex: a putative docking factor at multiple steps of vesicular transport to the vacuole of Saccharomyces cerevisiae.

OpenAIRE

Srivastava, A; Woolford, C A; Jones, E W

2000-01-01

Pep3p and Pep5p are known to be necessary for trafficking of hydrolase precursors to the vacuole and for vacuolar biogenesis. These proteins are present in a hetero-oligomeric complex that mediates transport at the vacuolar membrane. PEP5 interacts genetically with VPS8, implicating Pep5p in the earlier Golgi to endosome step and/or in recycling from the endosome to the Golgi. To understand further the cellular roles of Pep3p and Pep5p, we isolated and characterized a set of pep3 conditional ...

Thinking regionally: narrative, the medical humanities and region.

Science.gov (United States)

Waddington, Keir

2015-06-01

Drawing on multiple literatures from history, geography, anthropology, sociology and literature, this essay asks questions about what we mean by region and why narratives of region should matter to the medical humanities. The essay surveys how region can be used as a lens of analysis, exploring the various academic approaches to region and their limitations. It argues that regions are dynamic but also unstable as a category of analysis and are often used uncritically by scholars. In encouraging scholars working in the medical humanities to be aware that regions are not simple objective or analytical boxes, the essay shows how an awareness of region helps challenge metropolitan whiggism and ideas of core and periphery to give a more prominent place to hinterlands, market towns and rural environments. Furthermore, the essay considers how incorporating region into our understanding of illness can offer new insights. It demonstrates the need for scholars to be attuned to the narratives constructed around regions, suggesting that regions can be viewed as discursive formations that provide a frame for understanding both collective and personal ideas of, and responses to, health and illness, disease and healing, to create what Megan Davies calls a more nuanced 'intellectual cartography'. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Human endothelial progenitor cells internalize high-density lipoprotein.

Directory of Open Access Journals (Sweden)

Kaemisa Srisen

Full Text Available Endothelial progenitor cells (EPCs originate either directly from hematopoietic stem cells or from a subpopulation of monocytes. Controversial views about intracellular lipid traffic prompted us to analyze the uptake of human high density lipoprotein (HDL, and HDL-cholesterol in human monocytic EPCs. Fluorescence and electron microscopy were used to investigate distribution and intracellular trafficking of HDL and its associated cholesterol using fluorescent surrogates (bodipy-cholesterol and bodipy-cholesteryl oleate, cytochemical labels and fluorochromes including horseradish peroxidase and Alexa Fluor® 568. Uptake and intracellular transport of HDL were demonstrated after internalization periods from 0.5 to 4 hours. In case of HDL-Alexa Fluor® 568, bodipy-cholesterol and bodipy-cholesteryl oleate, a photooxidation method was carried out. HDL-specific reaction products were present in invaginations of the plasma membrane at each time of treatment within endocytic vesicles, in multivesicular bodies and at longer periods of uptake, also in lysosomes. Some HDL-positive endosomes were arranged in form of "strings of pearl"- like structures. HDL-positive multivesicular bodies exhibited intensive staining of limiting and vesicular membranes. Multivesicular bodies of HDL-Alexa Fluor® 568-treated EPCs showed multilamellar intra-vacuolar membranes. At all periods of treatment, labeled endocytic vesicles and organelles were apparent close to the cell surface and in perinuclear areas around the Golgi apparatus. No HDL-related particles could be demonstrated close to its cisterns. Electron tomographic reconstructions showed an accumulation of HDL-containing endosomes close to the trans-Golgi-network. HDL-derived bodipy-cholesterol was localized in endosomal vesicles, multivesicular bodies, lysosomes and in many of the stacked Golgi cisternae and the trans-Golgi-network Internalized HDL-derived bodipy-cholesteryl oleate was channeled into the lysosomal

Insulin-like growth factor 1 (IGF-1 enhances the protein expression of CFTR.

Directory of Open Access Journals (Sweden)

Ha Won Lee

Full Text Available Low levels of insulin-like growth factor 1 (IGF-1 have been observed in the serum of cystic fibrosis (CF patients. However, the effects of low serum IGF-1 on the cystic fibrosis transmembrane conductance regulator (CFTR, whose defective function is the primary cause of cystic fibrosis, have not been studied. Here, we show in human cells that IGF-1 increases the steady-state levels of mature wildtype CFTR in a CFTR-associated ligand (CAL- and TC10-dependent manner; moreover, IGF-1 increases CFTR-mediated chloride transport. Using an acceptor photobleaching fluorescence resonance energy transfer (FRET assay, we have confirmed the binding of CAL and CFTR in the Golgi. We also show that CAL overexpression inhibits forskolin-induced increases in the cell-surface expression of CFTR. We found that IGF-1 activates TC10, and active TC10 alters the functional association between CAL and CFTR. Furthermore, IGF-1 and active TC10 can reverse the CAL-mediated reduction in the cell-surface expression of CFTR. IGF-1 does not increase the expression of ΔF508 CFTR, whose processing is arrested in the ER. This finding is consistent with our observation that IGF-1 alters the functional interaction of CAL and CFTR in the Golgi. However, when ΔF508 CFTR is rescued with low temperature or the corrector VRT-325 and proceeds to the Golgi, IGF-1 can increase the expression of the rescued ΔF508 CFTR. Our data support a model indicating that CAL-CFTR binding in the Golgi inhibits CFTR trafficking to the cell surface, leading CFTR to the degradation pathway instead. IGF-1-activated TC10 changes the interaction of CFTR and CAL, allowing CFTR to progress to the plasma membrane. These findings offer a potential strategy using a combinational treatment of IGF-1 and correctors to increase the post-Golgi expression of CFTR in cystic fibrosis patients bearing the ΔF508 mutation.

Regional scheme for the connection to the grid of renewable energies: for the Hauts-de-France region, for the Nord-Pas-de-Calais region, for the Picardy region, the Alsace region, the Aquitaine region, the Auvergne region, the Lower-Normandy region, the Burgundy region, the Brittany region, the Centre-Val-de-Loire region, the Champagne-Ardennes region, the Franche-Comte region, the Upper Normandy region, the Ile-de-France region, the Languedoc-Roussillon region, the Lorraine region, the Midi-Pyrenees region, the Provence-Alps-Cote d'Azur region, the Pays-de-la-Loire region, the Poitou-Charentes region, the Rhone-Alps region. Technical and financial status of the scheme implementation

International Nuclear Information System (INIS)

2017-01-01

This document gathers reports related to all French regions. Each one addresses the elaboration of the concerned regional scheme of connection of renewable energies to the distribution network (French acronym: S3REnR) which aims at anticipating and planning evolutions of electrical networks which are necessary for the integration of renewable energies. Illustrated by maps, tables and graphs, these reports propose indications of energy production locations, an identification of planned works, a presentation of the concerned region, of its existing grid and projects, an overview of the scheme content (initial status, results of consultations, adopted strategies, planned works), and an overview of the scheme implementation status

Dvigateli regional'nogo stroitel'stva. Vlijanie regional'nyh politicheskih organizacij na sotrudnichestvo universitetov v regione Baltijskogo morja [Motors for regional development: impact on regional political organizations on the university cooperation in the Baltic Sea region

Directory of Open Access Journals (Sweden)

Ewert Stefan

2010-01-01

Full Text Available Educational co-operation is one of the main aspects of the regional political agenda in the Baltic Sea Region. The article analyzes the political impact of the organizations, as perceived by the universities in the region and political decision-makers on national and regional levels. Based on the success of the OECD in becoming an influential actor in educational policies, this article discusses different strategies for the regional political organizations to enhance their influence.

Regional employment growth, shocks and regional industrial resilience

DEFF Research Database (Denmark)

Holm, Jacob Rubæk; Østergaard, Christian Richter

2013-01-01

The resilience of regional industries to economic shocks has gained a lot of attention in evolutionary economic geography recently. This paper uses a novel quantitative approach to investigate the regional industrial resilience of the Danish ICT sector to the shock following the burst of the dot......-com bubble. It is shown that regions characterised by small and young ICT service companies were more adaptable and grew more than others, while diversity and urbanisation increased the sensitivity to the business cycle after the shock. Different types of resilient regions are found: adaptively resilient......, rigidly resilient, entrepreneurially resilient and non-resilient regions....

Secretion of 35SO4-labeled proteins from isolated rat hepatocytes

International Nuclear Information System (INIS)

von Wuertemberg, M.M.F.; Fries, E.

1989-01-01

Sulfation is a Golgi-specific modification of secretory proteins. We have characterized the proteins that are labeled with 35 SO 4 in cultures of rat hepatocytes and studied their transport to the medium. Analysis by polyacrylamide gel electrophoresis showed that of the five most heavily labeled proteins, four had well-defined mobilities--apparent molecular masses of 188, 142, 125, and 82 kDa--whereas one was electrophoretically heterogeneous--apparent molecular mass of 35-45 kDa. Judging by their relatively high resistance to acid treatment, the sulfate residues in the 125- and 35-45-kDa proteins were linked to carbohydrate. Some of the secreted proteins were sialylated. In samples of pulse-labeled cells, there appeared to be no unsialylated forms, indicating that sulfation occurred after sialylation, presumably in the trans Golgi. Kinetic experiments showed that the cellular half-life was the same for all the sulfated proteins--about 8 min--consistent with the idea that transport from the Golgi complex to the cell surface occurs by liquid bulk flow

N-Glycosylation instead of cholesterol mediates oligomerization and apical sorting of GPI-APs in FRT cells.

Science.gov (United States)

Imjeti, Naga Salaija; Lebreton, Stéphanie; Paladino, Simona; de la Fuente, Erwin; Gonzalez, Alfonso; Zurzolo, Chiara

2011-12-01

Sorting of glycosylphosphatidyl-inositol--anchored proteins (GPI-APs) in polarized epithelial cells is not fully understood. Oligomerization in the Golgi complex has emerged as the crucial event driving apical segregation of GPI-APs in two different kind of epithelial cells, Madin-Darby canine kidney (MDCK) and Fisher rat thyroid (FRT) cells, but whether the mechanism is conserved is unknown. In MDCK cells cholesterol promotes GPI-AP oligomerization, as well as apical sorting of GPI-APs. Here we show that FRT cells lack this cholesterol-driven oligomerization as apical sorting mechanism. In these cells both apical and basolateral GPI-APs display restricted diffusion in the Golgi likely due to a cholesterol-enriched membrane environment. It is striking that N-glycosylation is the critical event for oligomerization and apical sorting of GPI-APs in FRT cells but not in MDCK cells. Our data indicate that at least two mechanisms exist to determine oligomerization in the Golgi leading to apical sorting of GPI-APs. One depends on cholesterol, and the other depends on N-glycosylation and is insensitive to cholesterol addition or depletion.

Regional Geography is Dead. Long Live Regional Geography!

Czech Academy of Sciences Publication Activity Database

Vaishar, Antonín; Werner, M.

2006-01-01

Roč. 14, č. 3 (2006), s. 2-8 ISSN 1210-8812 Institutional research plan: CEZ:AV0Z30860518 Keywords : regional geography * regions * geography * methodology * Ostrava region Subject RIV: DE - Earth Magnetism, Geodesy, Geography

Endogenous RGS14 is a cytoplasmic-nuclear shuttling protein that localizes to juxtanuclear membranes and chromatin-rich regions of the nucleus

Science.gov (United States)

Hepler, John R.

2017-01-01

Regulator of G protein signaling 14 (RGS14) is a multifunctional scaffolding protein that integrates G protein and H-Ras/MAPkinase signaling pathways to regulate synaptic plasticity important for hippocampal learning and memory. However, to date, little is known about the subcellular distribution and roles of endogenous RGS14 in a neuronal cell line. Most of what is known about RGS14 cellular behavior is based on studies of tagged, recombinant RGS14 ectopically overexpressed in unnatural host cells. Here, we report for the first time a comprehensive assessment of the subcellular distribution and dynamic localization of endogenous RGS14 in rat B35 neuroblastoma cells. Using confocal imaging and 3D-structured illumination microscopy, we find that endogenous RGS14 localizes to subcellular compartments not previously recognized in studies of recombinant RGS14. RGS14 localization was observed most notably at juxtanuclear membranes encircling the nucleus, at nuclear pore complexes (NPC) on both sides of the nuclear envelope and within intranuclear membrane channels, and within both chromatin-poor and chromatin-rich regions of the nucleus in a cell cycle-dependent manner. In addition, a subset of nuclear RGS14 localized adjacent to active RNA polymerase II. Endogenous RGS14 was absent from the plasma membrane in resting cells; however, the protein could be trafficked to the plasma membrane from juxtanuclear membranes in endosomes derived from ER/Golgi, following constitutive activation of endogenous RGS14 G protein binding partners using AlF4¯. Finally, our findings show that endogenous RGS14 behaves as a cytoplasmic-nuclear shuttling protein confirming what has been shown previously for recombinant RGS14. Taken together, the findings highlight possible cellular roles for RGS14 not previously recognized that are distinct from the regulation of conventional GPCR-G protein signaling, in particular undefined roles for RGS14 in the nucleus. PMID:28934222

A Polymorphic Antioxidant Response Element Links NRF2/sMAF Binding to Enhanced MAPT Expression and Reduced Risk of Parkinsonian Disorders

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Xuting Wang

2016-04-01

Full Text Available The NRF2/sMAF protein complex regulates the oxidative stress response by occupying cis-acting enhancers containing an antioxidant response element (ARE. Integrating genome-wide maps of NRF2/sMAF occupancy with disease-susceptibility loci, we discovered eight polymorphic AREs linked to 14 highly ranked disease-risk SNPs in individuals of European ancestry. Among these SNPs was rs242561, located within a regulatory region of the MAPT gene (encoding microtubule-associated protein Tau. It was consistently occupied by NRF2/sMAF in multiple experiments and its strong-binding allele associated with higher mRNA levels in cell lines and human brain tissue. Induction of MAPT transcription by NRF2 was confirmed using a human neuroblastoma cell line and a Nrf2-deficient mouse model. Most importantly, rs242561 displayed complete linkage disequilibrium with a highly protective allele identified in multiple GWASs of progressive supranuclear palsy, Parkinson’s disease, and corticobasal degeneration. These observations suggest a potential role for NRF2/sMAF in tauopathies and a possible role for NRF2 pathway activators in disease prevention.