scholarly journals ER exit sites in Drosophila display abundant ER-Golgi vesicles and pearled tubes but no megacarriers

2021 ◽  
Author(s):  
Ke Yang ◽  
Min Liu ◽  
Zhi Feng ◽  
Marta Rojas ◽  
Lingjian Zhou ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Fat Body ◽  
Retrograde Transport ◽  
Imaginal Discs ◽  
Membrane Structures ◽  
Molecular Events ◽  
Golgi Region ◽  
Er Exit Sites ◽  
Essential Questions ◽  
Intermediate Compartment

AbstractSecretory cargos are collected at ER exit sites (ERES) before transport to the Golgi apparatus. Decades of research have provided many details of the molecular events underlying ER-Golgi exchanges. Essential questions, however, remain about the organization of the ER-Golgi interface in cells and the type of membrane structures mediating traffic from ERES. To investigate these, we used transgenic tagging in Drosophila flies, 3D-SIM and FIB-SEM to characterize ERES-Golgi units in collagen-producing fat body, imaginal discs and imaginal discs overexpressing ERES determinant Tango1. We found in front of ERES a pre-cis-Golgi region involved in both anterograde and retrograde transport. This pre-cis-Golgi is continuous with the rest of the Golgi, not a separate intermediate compartment or collection of large carriers, for which we found no evidence. We found, however, many vesicles, as well as pearled tubules connecting ERES and Golgi.

scholarly journals Retrograde Transport from the Pre-Golgi Intermediate Compartment and the Golgi Complex Is Affected by the Vacuolar H+-ATPase Inhibitor Bafilomycin A1

1998 ◽  
Vol 9 (12) ◽  
pp. 3561-3578 ◽  
Author(s):  
Harri Palokangas ◽  
Ming Ying ◽  
Kalervo Väänänen ◽  
Jaakko Saraste
Keyword(s):  
Brefeldin A ◽  
Retrograde Transport ◽  
Small Gtpase ◽  
Bafilomycin A1 ◽  
Atpase Inhibitor ◽  
Marker Proteins ◽  
Golgi Region ◽  
Intermediate Compartment ◽  
Acidic Compartments

The effect of the vacuolar H+-ATPase inhibitor bafilomycin A1 (Baf A1) on the localization of pre-Golgi intermediate compartment (IC) and Golgi marker proteins was used to study the role of acidification in the function of early secretory compartments. Baf A1 inhibited both brefeldin A- and nocodazole-induced retrograde transport of Golgi proteins to the endoplasmic reticulum (ER), whereas anterograde ER-to-Golgi transport remained largely unaffected. Furthermore, p58/ERGIC-53, which normally cycles between the ER, IC, and cis-Golgi, was arrested in pre-Golgi tubules and vacuoles, and the number of p58-positive ∼80-nm Golgi (coatomer protein I) vesicles was reduced, suggesting that the drug inhibits the retrieval of the protein from post-ER compartments. In parallel, redistribution of β-coatomer protein from the Golgi to peripheral pre-Golgi structures took place. The small GTPase rab1p was detected in short pre-Golgi tubules in control cells and was efficiently recruited to the tubules accumulating in the presence of Baf A1. In contrast, these tubules showed no enrichment of newly synthesized, anterogradely transported proteins, indicating that they participate in retrograde transport. These results suggest that the pre-Golgi structures contain an active H+-ATPase that regulates retrograde transport at the ER–Golgi boundary. Interestingly, although Baf A1 had distinct effects on peripheral pre-Golgi structures, only more central, p58-containing elements accumulated detectable amounts of 3-(2,4-dinitroanilino)-3′-amino-N-methyldipropylamine (DAMP), a marker for acidic compartments, raising the possibility that the lumenal pH of the pre-Golgi structures gradually changes in parallel with their translocation to the Golgi region.

scholarly journals The Mammalian Protein (rbet1) Homologous to Yeast Bet1p Is Primarily Associated with the Pre-Golgi Intermediate Compartment and Is Involved in Vesicular Transport from the Endoplasmic Reticulum to the Golgi Apparatus

1997 ◽  
Vol 139 (5) ◽  
pp. 1157-1168 ◽  
Author(s):  
Tao Zhang ◽  
Siew Heng Wong ◽  
Bor Luen Tang ◽  
Yue Xu ◽  
Frank Peter ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
G Protein ◽  
Vesicular Transport ◽  
Dependent Manner ◽  
Golgi Transport ◽  
Golgi Region ◽  
Intermediate Compartment ◽  
Kdel Receptor ◽  
Mammalian Protein

Yeast Bet1p participates in vesicular transport from the endoplasmic reticulum to the Golgi apparatus and functions as a soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) associated with ER-derived vesicles. A mammalian protein (rbet1) homologous to Bet1p was recently identified, and it was concluded that rbet1 is associated with the Golgi apparatus based on the subcellular localization of transiently expressed epitope-tagged rbet1. In the present study using rabbit antibodies raised against the cytoplasmic domain of rbet1, we found that the majority of rbet1 is not associated with the Golgi apparatus as marked by the Golgi mannosidase II in normal rat kidney cells. Rather, rbet1 is predominantly associated with vesicular spotty structures that concentrate in the peri-Golgi region but are also present throughout the cytoplasm. These structures colocalize with the KDEL receptor and ERGIC-53, which are known to be enriched in the intermediate compartment. When the Golgi apparatus is fragmented by nocodazole treatment, a significant portion of rbet1 is not colocalized with structures marked by Golgi mannosidase II or the KDEL receptor. Association of rbet1 in cytoplasmic spotty structures is apparently not altered by preincubation of cells at 15°C. However, upon warming up from 15 to 37°C, rbet1 concentrates into the peri-Golgi region. Furthermore, rbet1 colocalizes with vesicular stomatitis virus G-protein en route from the ER to the Golgi. Antibodies against rbet1 inhibit in vitro transport of G-protein from the ER to the Golgi apparatus in a dose-dependent manner. This inhibition can be neutralized by preincubation of antibodies with recombinant rbet1. EGTA is known to inhibit ER-Golgi transport at a stage after vesicle docking but before the actual fusion event. Antibodies against rbet1 inhibit ER-Golgi transport only when they are added before the EGTA-sensitive stage. These results suggest that rbet1 may be involved in the docking process of ER- derived vesicles with the cis-Golgi membrane.

scholarly journals 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

2012 ◽  
Vol 23 (16) ◽  
pp. 3203-3214 ◽  
Author(s):  
Yoko Ito ◽  
Tomohiro Uemura ◽  
Keiko Shoda ◽  
Masaru Fujimoto ◽  
Takashi Ueda ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Fluorescent Proteins ◽  
Plant Cells ◽  
Brefeldin A ◽  
Eukaryotic Cells ◽  
Er Exit Sites ◽  
Intermediate Compartment ◽  
Golgi Protein ◽  
And Function

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.

scholarly journals Branched Actin Maintains Acetylated Microtubule Network in the Early Secretory Pathway

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Azumi Yoshimura ◽  
Stéphanie Miserey-Lenkei ◽  
Evelyne Coudrier ◽  
Bruno Goud
Keyword(s):  
Golgi Apparatus ◽  
Transport Process ◽  
Actin Polymerization ◽  
Secretory Pathway ◽  
Microtubule Network ◽  
Early Secretory Pathway ◽  
Golgi Transport ◽  
Er Exit Sites ◽  
Intermediate Compartment ◽  
Stable Network

In the early secretory pathway, the delivery of anterograde cargoes from the endoplasmic reticulum (ER) exit sites (ERES) to the Golgi apparatus is a multi-step transport process occurring via the ER-Golgi intermediate compartment (IC, also called ERGIC). While the role microtubules in ER-to-Golgi transport has been well established, how the actin cytoskeleton contributes to this process remains poorly understood. Here, we report that Arp2/3 inhibition affects the network of acetylated microtubules around the Golgi and induces the accumulation of unusually long RAB1/GM130-positive carriers around the centrosome. These long carriers are less prone to reach the Golgi apparatus, and arrival of anterograde cargoes to the Golgi is decreased upon Arp2/3 inhibition. Our data suggest that Arp2/3-dependent actin polymerization maintains a stable network of acetylated microtubules, which ensures efficient cargo trafficking at the late stage of ER to Golgi transport.

scholarly journals An Ordered Inheritance Strategy for the Golgi Apparatus: Visualization of Mitotic Disassembly Reveals a Role for the Mitotic Spindle

1998 ◽  
Vol 141 (4) ◽  
pp. 955-966 ◽  
Author(s):  
David T. Shima ◽  
Noemí Cabrera-Poch ◽  
Rainer Pepperkok ◽  
Graham Warren
Keyword(s):  
Golgi Apparatus ◽  
Mitotic Spindle ◽  
Fluorescent Protein ◽  
Retrograde Transport ◽  
Early Prophase ◽  
Nuclear Envelope Breakdown ◽  
Microtubule Disruption ◽  
Low Copy Number ◽  
Er Exit Sites ◽  
Green Fluorescent

During mitosis, the ribbon of the Golgi apparatus is transformed into dispersed tubulo-vesicular membranes, proposed to facilitate stochastic inheritance of this low copy number organelle at cytokinesis. Here, we have analyzed the mitotic disassembly of the Golgi apparatus in living cells and provide evidence that inheritance is accomplished through an ordered partitioning mechanism. Using a Sar1p dominant inhibitor of cargo exit from the endoplasmic reticulum (ER), we found that the disassembly of the Golgi observed during mitosis or microtubule disruption did not appear to involve retrograde transport of Golgi residents to the ER and subsequent reorganization of Golgi membrane fragments at ER exit sites, as has been suggested. Instead, direct visualization of a green fluorescent protein (GFP)-tagged Golgi resident through mitosis showed that the Golgi ribbon slowly reorganized into 1–3-μm fragments during G2/early prophase. A second stage of fragmentation occurred coincident with nuclear envelope breakdown and was accompanied by the bulk of mitotic Golgi redistribution. By metaphase, mitotic Golgi dynamics appeared to cease. Surprisingly, the disassembly of mitotic Golgi fragments was not a random event, but involved the reorganization of mitotic Golgi by microtubules, suggesting that analogous to chromosomes, the Golgi apparatus uses the mitotic spindle to ensure more accurate partitioning during cytokinesis.

scholarly journals Homeostatic regulation of STING by retrograde membrane traffic to the ER

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kojiro Mukai ◽  
Emari Ogawa ◽  
Rei Uematsu ◽  
Yoshihiko Kuchitsu ◽  
Fumika Kiku ◽  
...  
Keyword(s):  
Resting State ◽  
Complex I ◽  
Membrane Traffic ◽  
Retrograde Transport ◽  
Homeostatic Regulation ◽  
Gene Encoding ◽  
Downstream Signaling ◽  
Intermediate Compartment ◽  
Downstream Signaling Pathway ◽  
Copa Syndrome

AbstractCoat protein complex I (COP-I) mediates the retrograde transport from the Golgi apparatus to the endoplasmic reticulum (ER). Mutation of the COPA gene, encoding one of the COP-I subunits (α-COP), causes an immune dysregulatory disease known as COPA syndrome. The molecular mechanism by which the impaired retrograde transport results in autoinflammation remains poorly understood. Here we report that STING, an innate immunity protein, is a cargo of the retrograde membrane transport. In the presence of the disease-causative α-COP variants, STING cannot be retrieved back to the ER from the Golgi. The forced Golgi residency of STING results in the cGAS-independent and palmitoylation-dependent activation of the STING downstream signaling pathway. Surf4, a protein that circulates between the ER/ ER-Golgi intermediate compartment/ Golgi, binds STING and α-COP, and mediates the retrograde transport of STING to the ER. The STING/Surf4/α-COP complex is disrupted in the presence of the disease-causative α-COP variant. We also find that the STING ligand cGAMP impairs the formation of the STING/Surf4/α-COP complex. Our results suggest a homeostatic regulation of STING at the resting state by retrograde membrane traffic and provide insights into the pathogenesis of COPA syndrome.

Retrograde transport from the golgi apparatus to the endoplasmic reticulum

1998 ◽  
Vol 90 (1) ◽  
pp. 116-116
Author(s):  
François Letourneur ◽  
Pierre Cosson
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Retrograde Transport

scholarly journals Characterization of the budding compartment of mouse hepatitis virus: evidence that transport from the RER to the Golgi complex requires only one vesicular transport step

1994 ◽  
Vol 124 (1) ◽  
pp. 55-70 ◽  
Author(s):  
J Krijnse-Locker ◽  
M Ericsson ◽  
PJ Rottier ◽  
G Griffiths
Keyword(s):  
Golgi Complex ◽  
Hepatitis Virus ◽  
Vesicular Transport ◽  
Helix Pomatia ◽  
M Protein ◽  
Membrane Structures ◽  
Golgi Stack ◽  
Permeabilized Cells ◽  
Intermediate Compartment ◽  
Rough Er

Mouse hepatitis coronavirus (MHV) buds into pleomorphic membrane structures with features expected of the intermediate compartment between the ER and the Golgi complex. Here, we characterize the MHV budding compartment in more detail in mouse L cells using streptolysin O (SLO) permeabilization which allowed us to better visualize the membrane structures at the ER-Golgi boundary. The MHV budding compartment shares membrane continuities with the rough ER as well as with cisternal elements on one side of the Golgi stack. It also labeled with p58 and rab2, two markers of the intermediate compartment, and with PDI, usually considered to be a marker of the rough ER. The membranes of the budding compartment, as well as the budding virions themselves, but not the rough ER, labeled with the N-acetyl-galactosamine (GalNAc)-specific lectin Helix pomatia. When the SLO-permeabilized cells were treated with guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), the budding compartment accumulated a large number of beta-cop-containing buds and vesicular profiles. Complementary biochemical experiments were carried out to determine whether vesicular transport was required for the newly synthesized M protein, that contains only O-linked oligosaccharides, to acquire first, GalNAc and second, the Golgi modifications galactose and sialic acid. The results from both in vivo studies and from the use of SLO-permeabilized cells showed that, while GalNAc addition occurred under conditions which block vesicular transport, both cytosol and ATP were prerequisites for the M protein oligosaccharides to acquire Golgi modifications. Collectively, our data argue that transport from the rough ER to the Golgi complex requires only one vesicular transport step and that the intermediate compartment is a specialized domain of the endoplasmatic reticulum that extends to the first cisterna on the cis side of the Golgi stack.

A Study of the Osmium Techniques for the ‘Golgi Apparatus’

1954 ◽  
Vol s3-95 (31) ◽  
pp. 383-388
Author(s):  
JOHN R. BAKER
Keyword(s):  
Epithelial Cell ◽  
Golgi Apparatus ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial ◽  
Black Precipitate ◽  
Golgi Region

The paper is concerned with the action of the osmium techniques for the ‘Golgi apparatus’ on the intestinal epithelial cell of the mouse. It is shown that, when the fixative has acted, there are many separate lipide spheres in the ‘Golgi’ region. During postosmication the spaces between these spheres are filled up with a black precipitate. This black precipitate does not represent the distribution of lipide material.

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