Faculty Opinions recommendation of Grab a Golgi: laser trapping of Golgi bodies reveals in vivo interactions with the endoplasmic reticulum.

2009 ◽  
Author(s):  
Federica Brandizzi
Keyword(s):  
Endoplasmic Reticulum ◽  
Laser Trapping ◽  
Golgi Bodies

scholarly journals Grab a Golgi: Laser Trapping of Golgi Bodies Revealsin vivoInteractions with the Endoplasmic Reticulum

Traffic ◽  
2009 ◽  
Vol 10 (5) ◽  
pp. 567-571 ◽  
Author(s):  
Imogen A. Sparkes ◽  
Tijs Ketelaar ◽  
Norbert C.A. de Ruijter ◽  
Chris Hawes
Keyword(s):  
Endoplasmic Reticulum ◽  
Laser Trapping ◽  
Golgi Bodies

An Ultra-Structural Study of Human Melanoma in Vivo and Vitro

1976 ◽  
Vol 34 ◽  
pp. 258-259
Author(s):  
James R. Gaylor ◽  
Fredda Schafer ◽  
Robert E. Nordquist
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Protein Aggregation ◽  
Structural Study ◽  
Human Melanoma ◽  
Protein Matrix ◽  
Early Form ◽  
Endoplasmic Reticulum Protein ◽  
Mitochondrial Origin

Several theories on the origin of the melanosome exist. These include the Golgi origin theory, in which a tyrosinase-rich protein is "packaged" by the Golgi apparatus, thus forming the early form of the melanosome. A second theory postulates a mitochondrial origin of melanosomes. Its author contends that the melanosome is a modified mitochondria which acquires melanin during its development. A third theory states that a pre-melanosome is formed in the smooth or rough endoplasmic reticulum. Protein aggregation is suggested by one author as a possible source of the melanosome. This fourth theory postulates that the melanosome originates when the protein products of several genetic loci aggregate in the cytoplasm of the melanocyte. It is this protein matrix on which the melanin is deposited. It was with these theories in mind that this project was undertaken.

scholarly journals Synaptotagmins at the endoplasmic reticulum–plasma membrane contact sites maintain diacylglycerol homeostasis during abiotic stress

2021 ◽  
Author(s):  
Noemi Ruiz-Lopez ◽  
Jessica Pérez-Sancho ◽  
Alicia Esteban del Valle ◽  
Richard P Haslam ◽  
Steffen Vanneste ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Abiotic Stress ◽  
Fluorescent Protein ◽  
Mechanical Damage ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Membrane Contact ◽  
Green Fluorescent

Abstract Endoplasmic reticulum-plasma membrane contact sites (ER-PM CS) play fundamental roles in all eukaryotic cells. Arabidopsis thaliana mutants lacking the ER-PM protein tether synaptotagmin1 (SYT1) exhibit decreased plasma membrane (PM) integrity under multiple abiotic stresses such as freezing, high salt, osmotic stress and mechanical damage. Here, we show that, together with SYT1, the stress-induced SYT3 is an ER-PM tether that also functions in maintaining PM integrity. The ER-PM CS localization of SYT1 and SYT3 is dependent on PM phosphatidylinositol-4-phosphate and is regulated by abiotic stress. Lipidomic analysis revealed that cold stress increased the accumulation of diacylglycerol at the PM in a syt1/3 double mutant relative to wild type while the levels of most glycerolipid species remain unchanged. Additionally, the SYT1-green fluorescent protein (GFP) fusion preferentially binds diacylglycerol in vivo with little affinity for polar glycerolipids. Our work uncovers a SYT-dependent mechanism of stress adaptation counteracting the detrimental accumulation of diacylglycerol at the PM produced during episodes of abiotic stress.

scholarly journals Dehydrodiisoeugenol inhibits colorectal cancer growth by endoplasmic reticulum stress-induced autophagic pathways

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Changhong Li ◽  
Kui Zhang ◽  
Guangzhao Pan ◽  
Haoyan Ji ◽  
Chongyang Li ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Endoplasmic Reticulum ◽  
Cell Growth ◽  
Er Stress ◽  
Cancer Cells ◽  
Tumor Xenograft ◽  
Anticancer Activities ◽  
Colorectal Cancer Cells

Abstract Background Dehydrodiisoeugenol (DEH), a novel lignan component extracted from nutmeg, which is the seed of Myristica fragrans Houtt, displays noticeable anti-inflammatory and anti-allergic effects in digestive system diseases. However, the mechanism of its anticancer activity in gastrointestinal cancer remains to be investigated. Methods In this study, the anticancer effect of DEH on human colorectal cancer and its underlying mechanism were evaluated. Assays including MTT, EdU, Plate clone formation, Soft agar, Flow cytometry, Electron microscopy, Immunofluorescence and Western blotting were used in vitro. The CDX and PDX tumor xenograft models were used in vivo. Results Our findings indicated that treatment with DEH arrested the cell cycle of colorectal cancer cells at the G1/S phase, leading to significant inhibition in cell growth. Moreover, DEH induced strong cellular autophagy, which could be inhibited through autophagic inhibitors, with a rction in the DEH-induced inhibition of cell growth in colorectal cancer cells. Further analysis indicated that DEH also induced endoplasmic reticulum (ER) stress and subsequently stimulated autophagy through the activation of PERK/eIF2α and IRE1α/XBP-1 s/CHOP pathways. Knockdown of PERK or IRE1α significantly decreased DEH-induced autophagy and retrieved cell viability in cells treated with DEH. Furthermore, DEH also exhibited significant anticancer activities in the CDX- and PDX-models. Conclusions Collectively, our studies strongly suggest that DEH might be a potential anticancer agent against colorectal cancer by activating ER stress-induced inhibition of autophagy.

scholarly journals Ceramide chain length–dependent protein sorting into selective endoplasmic reticulum exit sites

2020 ◽  
Vol 6 (50) ◽  
pp. eaba8237
Author(s):  
Sofia Rodriguez-Gallardo ◽  
Kazuo Kurokawa ◽  
Susana Sabido-Bozo ◽  
Alejandro Cortes-Gomez ◽  
Atsuko Ikeda ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Chain Length ◽  
Secretory Pathway ◽  
Protein Sorting ◽  
Endoplasmic Reticulum Membrane ◽  
Lipid Chain ◽  
Secretory Transport ◽  
Dependent Protein ◽  
Cellular Compartmentalization

Protein sorting in the secretory pathway is crucial to maintain cellular compartmentalization and homeostasis. In addition to coat-mediated sorting, the role of lipids in driving protein sorting during secretory transport is a longstanding fundamental question that still remains unanswered. Here, we conduct 3D simultaneous multicolor high-resolution live imaging to demonstrate in vivo that newly synthesized glycosylphosphatidylinositol-anchored proteins having a very long chain ceramide lipid moiety are clustered and sorted into specialized endoplasmic reticulum exit sites that are distinct from those used by transmembrane proteins. Furthermore, we show that the chain length of ceramide in the endoplasmic reticulum membrane is critical for this sorting selectivity. Our study provides the first direct in vivo evidence for lipid chain length–based protein cargo sorting into selective export sites of the secretory pathway.

scholarly journals Structure of the Lectin Mannose 6-Phosphate Receptor Homology (MRH) Domain of Glucosidase II, an Enzyme That Regulates Glycoprotein Folding Quality Control in the Endoplasmic Reticulum

2013 ◽  
Vol 288 (23) ◽  
pp. 16460-16475 ◽  
Author(s):  
Linda J. Olson ◽  
Ramiro Orsi ◽  
Solana G. Alculumbre ◽  
Francis C. Peterson ◽  
Ivan D. Stigliano ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Three Dimensional ◽  
Binding Pocket ◽  
Dimensional Structure ◽  
Mannose Residue ◽  
Glucosidase Ii ◽  
Mannose 6 Phosphate ◽  
First Time ◽  
Conserved Residue

Here we report for the first time the three-dimensional structure of a mannose 6-phosphate receptor homology (MRH) domain present in a protein with enzymatic activity, glucosidase II (GII). GII is involved in glycoprotein folding in the endoplasmic reticulum. GII removes the two innermost glucose residues from the Glc3Man9GlcNAc2 transferred to nascent proteins and the glucose added by UDP-Glc:glycoprotein glucosyltransferase. GII is composed of a catalytic GIIα subunit and a regulatory GIIβ subunit. GIIβ participates in the endoplasmic reticulum localization of GIIα and mediates in vivo enhancement of N-glycan trimming by GII through its C-terminal MRH domain. We determined the structure of a functional GIIβ MRH domain by NMR spectroscopy. It adopts a β-barrel fold similar to that of other MRH domains, but its binding pocket is the most shallow known to date as it accommodates a single mannose residue. In addition, we identified a conserved residue outside the binding pocket (Trp-409) present in GIIβ but not in other MRHs that influences GII glucose trimming activity.

scholarly journals Overexpression of CALNUC (Nucleobindin) Increases Agonist and Thapsigargin Releasable Ca2+ Storage in the Golgi

1999 ◽  
Vol 145 (2) ◽  
pp. 279-289 ◽  
Author(s):  
Ping Lin ◽  
Yong Yao ◽  
Robert Hofmeister ◽  
Roger Y. Tsien ◽  
Marilyn Gist Farquhar
Keyword(s):  
Endoplasmic Reticulum ◽  
Cho Cells ◽  
Binding Capacity ◽  
Binding Protein ◽  
Ip3 Receptor ◽  
Transfected Cells ◽  
Permeabilized Cells ◽  
Endoplasmic Reticulum Calcium ◽  
Golgi Protein

We previously demonstrated that CALNUC, a Ca2+-binding protein with two EF-hands, is the major Ca2+-binding protein in the Golgi by 45Ca2+ overlay (Lin, P., H. Le-Niculescu, R. Hofmeister, J.M. McCaffery, M. Jin, H. Henneman, T. McQuistan, L. De Vries, and M. Farquhar. 1998. J. Cell Biol. 141:1515–1527). In this study we investigated CALNUC's properties and the Golgi Ca2+ storage pool in vivo. CALNUC was found to be a highly abundant Golgi protein (3.8 μg CALNUC/mg Golgi protein, 2.5 × 105 CALNUC molecules/NRK cell) and to have a single high affinity, low capacity Ca2+-binding site (Kd = 6.6 μM, binding capacity = 1.1 μmol Ca2+/μmol CALNUC). 45Ca2+ storage was increased by 2.5- and 3-fold, respectively, in HeLa cells transiently overexpressing CALNUC-GFP and in EcR-CHO cells stably overexpressing CALNUC. Deletion of the first EF-hand α helix from CALNUC completely abolished its Ca2+-binding capability. CALNUC was correctly targeted to the Golgi in transfected cells as it colocalized and cosedimented with the Golgi marker, α-mannosidase II (Man II). Approximately 70% of the 45Ca2+ taken up by HeLa and CHO cells overexpressing CALNUC was released by treatment with thapsigargin, a sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) (Ca2+ pump) blocker. Stimulation of transfected cells with the agonist ATP or IP3 alone (permeabilized cells) also resulted in a significant increase in Ca2+ release from Golgi stores. By immunofluorescence, the IP3 receptor type 1 (IP3R-1) was distributed over the endoplasmic reticulum and codistributed with CALNUC in the Golgi. These results provide direct evidence that CALNUC binds Ca2+ in vivo and together with SERCA and IP3R is involved in establishment of the agonist-mobilizable Golgi Ca2+ store.

Interaction of the endoplasmic reticulum α1,2-mannosidase Mns1p with Rer1p using the split-ubiquitin system

2001 ◽  
Vol 114 (24) ◽  
pp. 4629-4635
Author(s):  
Michel J. Massaad ◽  
Annette Herscovics
Keyword(s):  
Endoplasmic Reticulum ◽  
Catalytic Domain ◽  
Transmembrane Domain ◽  
Protein A ◽  
Yeast Cells ◽  
Type Ii ◽  
Ubiquitin System ◽  
Endoplasmic Reticulum Protein ◽  
Split Ubiquitin

The α1,2-mannosidase Mns1p involved in the N-glycosidic pathway in Saccharomyces cerevisiae is a type II membrane protein of the endoplasmic reticulum. The localization of Mns1p depends on retrieval from the Golgi through a mechanism that involves Rer1p. A chimera consisting of the transmembrane domain of Mns1p fused to the catalytic domain of the Golgi α1,2-mannosyltransferase Kre2p was localized in the endoplasmic reticulum of Δpep4 cells and in the vacuoles of rer1/Δpep4 by indirect immunofluorescence. The split-ubiquitin system was used to determine if there is an interaction between Mns1p and Rer1p in vivo. Co-expression of NubG-Mns1p and Rer1p-Cub-protein A-lexA-VP16 in L40 yeast cells resulted in cleavage of the reporter molecule, protein A-lexA-VP16, detected by western blot analysis and by expression of β-galactosidase activity. Sec12p, another endoplasmic reticulum protein that depends on Rer1p for its localization, also interacted with Rer1p using the split-ubiquitin assay, whereas the endoplasmic reticulum protein Ost1p showed no interaction. A weak interaction was observed between Alg5p and Rer1p. These results demonstrate that the transmembrane domain of Mns1p is sufficient for Rer1p-dependent endoplasmic reticulum localization and that Mns1p and Rer1p interact. Furthermore, the split-ubiquitin system demonstrates that the C-terminal of Rer1p is in the cytosol.

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