Indirect immunofluorescence images of poliovirus-infected cells. Green, viral 2B protein; Red, glibenclamide BODIPY-TR (endoplasmic reticulum); Cyan, TGN46 (trans-Golgi network)

2015 ◽  
Vol 59 (6) ◽  
pp. i-i
Keyword(s):  
Endoplasmic Reticulum ◽  
Indirect Immunofluorescence ◽  
Trans Golgi Network ◽  
2B Protein ◽  
Infected Cells ◽  
Golgi Network

scholarly journals Detection of angiotensin II‐induced Ras activation in the trans‐Golgi network and the endoplasmic reticulum using BRET‐based biosensors

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Laszló Hunyady ◽  
Eszter Soltész‐Katona ◽  
László Erdélyi ◽  
Péter Várnai ◽  
András Balla
Keyword(s):  
Endoplasmic Reticulum ◽  
Angiotensin Ii ◽  
Trans Golgi Network ◽  
Ras Activation ◽  
Golgi Network

scholarly journals A new role for RINT-1 in SNARE complex assembly at the trans-Golgi network in coordination with the COG complex

2013 ◽  
Vol 24 (18) ◽  
pp. 2907-2917 ◽  
Author(s):  
Kohei Arasaki ◽  
Daichi Takagi ◽  
Akiko Furuno ◽  
Miwa Sohda ◽  
Yoshio Misumi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Trafficking ◽  
Retrograde Transport ◽  
Snare Complex ◽  
Initial Contact ◽  
Complex Assembly ◽  
Trans Golgi Network ◽  
Cog Complex ◽  
Protein Receptor ◽  
Golgi Network

Docking and fusion of transport vesicles/carriers with the target membrane involve a tethering factor–mediated initial contact followed by soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE)–catalyzed membrane fusion. The multisubunit tethering CATCHR family complexes (Dsl1, COG, exocyst, and GARP complexes) share very low sequence homology among subunits despite likely evolving from a common ancestor and participate in fundamentally different membrane trafficking pathways. Yeast Tip20, as a subunit of the Dsl1 complex, has been implicated in retrograde transport from the Golgi apparatus to the endoplasmic reticulum. Our previous study showed that RINT-1, the mammalian counterpart of yeast Tip20, mediates the association of ZW10 (mammalian Dsl1) with endoplasmic reticulum–localized SNARE proteins. In the present study, we show that RINT-1 is also required for endosome-to–trans-Golgi network trafficking. RINT-1 uncomplexed with ZW10 interacts with the COG complex, another member of the CATCHR family complex, and regulates SNARE complex assembly at the trans-Golgi network. This additional role for RINT-1 may in part reflect adaptation to the demand for more diverse transport routes from endosomes to the trans-Golgi network in mammals compared with those in a unicellular organism, yeast. The present findings highlight a new role of RINT-1 in coordination with the COG complex.

scholarly journals Endoplasmic reticulum and trans-Golgi network generate distinct populations of Alzheimer beta -amyloid peptides

1999 ◽  
Vol 96 (2) ◽  
pp. 742-747 ◽  
Author(s):  
J. P. Greenfield ◽  
J. Tsai ◽  
G. K. Gouras ◽  
B. Hai ◽  
G. Thinakaran ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Beta Amyloid ◽  
Amyloid Peptides ◽  
Trans Golgi Network ◽  
Golgi Network

scholarly journals CARTS biogenesis requires VAP–lipid transfer protein complexes functioning at the endoplasmic reticulum–Golgi interface

2015 ◽  
Vol 26 (25) ◽  
pp. 4686-4699 ◽  
Author(s):  
Yuichi Wakana ◽  
Richika Kotake ◽  
Nanako Oyama ◽  
Motohide Murate ◽  
Toshihide Kobayashi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Protein ◽  
Cell Surface ◽  
Lipid Transfer Protein ◽  
Protein Complexes ◽  
Lipid Transfer ◽  
Trans Golgi Network ◽  
Transfer Protein ◽  
Membrane Contact Sites ◽  
Golgi Network

Vesicle-associated membrane protein–associated protein (VAP) is an endoplasmic reticulum (ER)-resident integral membrane protein that controls a nonvesicular mode of ceramide and cholesterol transfer from the ER to the Golgi complex by interacting with ceramide transfer protein and oxysterol-binding protein (OSBP), respectively. We report that VAP and its interacting proteins are required for the processing and secretion of pancreatic adenocarcinoma up-regulated factor, whose transport from the trans-Golgi network (TGN) to the cell surface is mediated by transport carriers called “carriers of the trans-Golgi network to the cell surface” (CARTS). In VAP-depleted cells, diacylglycerol level at the TGN was decreased and CARTS formation was impaired. We found that VAP forms a complex with not only OSBP but also Sac1 phosphoinositide phosphatase at specialized ER subdomains that are closely apposed to the trans-Golgi/TGN, most likely reflecting membrane contact sites. Immobilization of ER–Golgi contacts dramatically reduced CARTS production, indicating that association–dissociation dynamics of the two membranes are important. On the basis of these findings, we propose that the ER–Golgi contacts play a pivotal role in lipid metabolism to control the biogenesis of transport carriers from the TGN.

Differential effects of temperature blockade on the proteolytic processing of three secretory granule-associated proteins

1994 ◽  
Vol 107 (3) ◽  
pp. 737-745 ◽  
Author(s):  
S.L. Milgram ◽  
R.E. Mains
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Pathway ◽  
Proteolytic Processing ◽  
Prohormone Convertase ◽  
Trans Golgi Network ◽  
Processing Enzymes ◽  
Prohormone Convertase 1 ◽  
Associated Proteins ◽  
Mouse Pituitary ◽  
Golgi Network

Vesicular transport within the secretory pathway can be arrested by incubating cells at 15 degrees C or 20 degrees C to block exit from the endoplasmic reticulum or trans-Golgi network, respectively. Using this powerful tool we have compared the intracellular sites of endoproteolytic processing of proopiomelanocortin and two prohormone processing enzymes in AtT-20 mouse pituitary corticotrope tumor cells. For comparison, proopiomelanocortin processing was also evaluated in primary neurointermediate pituitary cultures. AtT-20 cells synthesize and store endogenous proopiomelanocortin and prohormone convertase 1; AtT-20 cells expressing high levels of integral membrane or soluble peptidylglycine alpha-amidating monooxygenase were generated by stable transfection. Cells were incubated with [35S]methionine and chased at 4 degrees C, 15 degrees C, 20 degrees C or 37 degrees C. The endoproteolytic processing of peptidylglycine alpha-amidating mono-oxygenase, prohormone convertase 1, and proopiomelanocortin was compared following immunoprecipitation. Endoproteolytic processing of integral membrane and soluble peptidylglycine alpha-amidating monooxygenase proteins was completely blocked by incubation of cells at 20 degrees C. In contrast, prohormone convertase 1 processing from the 87 kDa precursor to the 81 kDa intermediate proceeded to completion at both 15 degrees C and 20 degrees C, while cleavage to generate the 63 kDa prohormone convertase 1 protein was completely blocked at 20 degrees C. In AtT-20 cells and neurointermediate pituitary cultures, generation of beta-lipotropin from proopiomelanocortin continued at a slow but significant rate at 20 degrees C, while processing of beta-lipotropin to beta-endorphin was blocked. Thus prohormone convertase 1 processing begins in the endoplasmic reticulum and is not completed until after the trans-Golgi network, while peptidylglycine alpha-amidating monooxygenase processing begins after the trans-Golgi network. Selected proopiomelanocortin cleavages begin before entry into immature granules.

Molecular chaperones in pancreatic tissue: the presence of cpn10, cpn60 and hsp70 in distinct compartments along the secretory pathway of the acinar cells

1994 ◽  
Vol 107 (3) ◽  
pp. 539-549 ◽  
Author(s):  
C.S. Velez-Granell ◽  
A.E. Arias ◽  
J.A. Torres-Ruiz ◽  
M. Bendayan
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Secretory Pathway ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Pancreatic Tissue ◽  
Secretory Proteins ◽  
Trans Golgi Network ◽  
Hsp70 Protein ◽  
Golgi Network

Three chaperones, the chaperonins cpn10 and cpn60, and the hsp70 protein, were revealed by immunochemistry and cytochemistry in pancreatic rat acinar cells. Western immunoblotting analysis of rat pancreas homogenates has shown that antibodies against cpn10, cpn60 and hsp70 protein recognize single protein bands of 25 kDa, 60 kDa and 70 kDa, respectively. Single bands for the cpn10 and cpn60 were also detected in pancreatic juice. Immunofluorescence studies on rat pancreatic tissue revealed a strong positive signal in the apical region of the acinar cells for cpn10 and cpn60, while an immunoreaction was detected at the juxtanuclear Golgi region with the anti-hsp70 antibody. Immunocytochemical gold labeling confirmed the presence of these three chaperones in distinct cell compartments of pancreatic acinar cells. Chaperonin 10 and cpn60 were located in the endoplasmic reticulum, Golgi apparatus, condensing vacuoles and secretory granules. Interestingly, the labeling for both cpn10 and cpn60 followed the increasing concentration gradient of secretory proteins along the RER-Golgi-granule secretory pathway. On the contrary, the labeling for hsp70 was mainly concentrated in the endoplasmic reticulum and the Golgi apparatus. In the latter, the hsp70 was found to be primary located in the trans-most cisternae and to colocalize with acid phosphatase in the trans-Golgi network. The three chaperones were also present in mitochondria. In view of the role played by the chaperones in the proper folding, sorting and aggregation of proteins, we postulate that hsp70 assists the adequate sorting and packaging of proteins from the ER to the trans-Golgi network while cpn10 and cpn60 play key roles in the proper packaging and aggregation of secretory proteins as well as, most probably, in the prevention of early enzyme activation in secretory granules.

scholarly journals Regulation of Microtubule-dependent Recycling at the Trans-Golgi Network by Rab6A and Rab6A'

2005 ◽  
Vol 16 (1) ◽  
pp. 162-177 ◽  
Author(s):  
Joanne Young ◽  
Tobias Stauber ◽  
Elaine del Nery ◽  
Isabelle Vernos ◽  
Rainer Pepperkok ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Small Interfering Rna ◽  
Small Gtpase ◽  
Present Evidence ◽  
Trans Golgi Network ◽  
Endosomal Recycling ◽  
Recycling Pathway ◽  
Golgi Network ◽  
Interfering Rna

The small GTPase rab6A but not the isoform rab6A' has previously been identified as a regulator of the COPI-independent recycling route that carries Golgi-resident proteins and certain toxins from the Golgi to the endoplasmic reticulum (ER). The isoform rab6A' has been implicated in Golgi-to-endosomal recycling. Because rab6A but not A', binds rabkinesin6, this motor protein is proposed to mediate COPI-independent recycling. We show here that both rab6A and rab6A' GTP-restricted mutants promote, with similar efficiency, a microtubule-dependent recycling of Golgi resident glycosylation enzymes upon overexpression. Moreover, we used small interfering RNA mediated down-regulation of rab6A and A' expression and found that reduced levels of rab6 perturbs organization of the Golgi apparatus and delays Golgi-to-ER recycling. Rab6-directed Golgi-to-ER recycling seems to require functional dynactin, as overexpression of p50/dynamitin, or a C-terminal fragment of Bicaudal-D, both known to interact with dynactin inhibit recycling. We further present evidence that rab6-mediated recycling seems to be initiated from the trans-Golgi network. Together, this suggests that a recycling pathway operates at the level of the trans-Golgi linking directly to the ER. This pathway would be the preferred route for both toxins and resident Golgi proteins.

Sign in / Sign up

Export Citation Format

Share Document