scholarly journals Overexpression of Arabidopsis AGD7 Causes Relocation of Golgi-Localized Proteins to the Endoplasmic Reticulum and Inhibits Protein Trafficking in Plant Cells

2007 ◽  
Vol 143 (4) ◽  
pp. 1601-1614 ◽  
Author(s):  
Myung Ki Min ◽  
Soo Jin Kim ◽  
Yansong Miao ◽  
Juyoun Shin ◽  
Liwen Jiang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Trafficking ◽  
Plant Cells

scholarly journals Rosa canina L. Can Restore Endoplasmic Reticulum Alterations, Protein Trafficking and Membrane Integrity in a Dextran Sulfate Sodium-Induced Inflammatory Bowel Disease Phenotype

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 441
Author(s):  
Dalanda Wanes ◽  
Mohamad Toutounji ◽  
Hichem Sebai ◽  
Sandra Rizk ◽  
Hassan Y. Naim
Keyword(s):  
Inflammatory Bowel Disease ◽  
Endoplasmic Reticulum ◽  
Lipid Rafts ◽  
Protein Trafficking ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Membrane Integrity ◽  
Membrane Glycoproteins ◽  
Rosa Canina ◽  
Inflammatory Bowel

Rosa canina L. is a natural polyphenol-rich medicinal plant that exhibits antioxidant and anti-inflammatory activities. Recent in vivo studies have demonstrated that a methanol extract of Rosa canina L. (RCME) has reversed an inflammatory bowel disease (IBD)-like phenotype that has been triggered by dextran sulfate sodium (DSS) in mice. In the current study, we investigated the effects of RCME on perturbations of cellular mechanisms induced by DSS-treatment of intestinal Caco-2 cells, including stress response in the endoplasmic reticulum (ER), protein trafficking and sorting as well as lipid rafts integrity and functional capacities of an intestinal enzyme. 6 days post-confluent cells were treated for 24 h with DSS (3%) or simultaneously with DSS (3%) and RCME (100 µg/mL) or exclusively with RCME (100 µg/mL) or not treated. The results obtained demonstrate the ability of RCME to counteract the substantial increase in the expression levels of several ER stress markers in DSS-treated cells. Concomitantly, the delayed trafficking of intestinal membrane glycoproteins sucrase-isomaltase (SI) and dipeptidyl peptidase 4 (DPP4) induced by DSS between the ER and the Golgi has been compromised by RCME. Furthermore, RCME restored the partially impaired polarized sorting of SI and DPP4 to the brush border membrane. An efficient sorting mechanism of SI and DPP4 is tightly associated with intact lipid rafts structures in the trans-Golgi network (TGN), which have been distorted by DSS and normalized by RCME. Finally, the enzymatic activities of SI are enhanced in the presence of RCME. Altogether, DSS treatment has triggered ER stress, impaired trafficking and function of membrane glycoproteins and distorted lipid rafts, all of which can be compromised by RCME. These findings indicate that the antioxidants in RCME act at two major sites in Caco-2 cells, the ER and the TGN and are thus capable of maintaining the membrane integrity by correcting the sorting of membrane-associated proteins.

scholarly journals Myosin-dependent endoplasmic reticulum motility and F-actin organization in plant cells

2010 ◽  
Vol 107 (15) ◽  
pp. 6894-6899 ◽  
Author(s):  
H. Ueda ◽  
E. Yokota ◽  
N. Kutsuna ◽  
T. Shimada ◽  
K. Tamura ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plant Cells ◽  
Actin Organization

scholarly journals Endoplasmic reticulum-localized CCX2 is required for osmotolerance by regulating ER and cytosolic Ca2+ dynamics in Arabidopsis

2018 ◽  
Vol 115 (15) ◽  
pp. 3966-3971 ◽  
Author(s):  
Massimiliano Corso ◽  
Fabrizio G. Doccula ◽  
J. Romário F. de Melo ◽  
Alex Costa ◽  
Nathalie Verbruggen
Keyword(s):  
Endoplasmic Reticulum ◽  
Osmotic Stress ◽  
Shoot Growth ◽  
Plant Cells ◽  
Loss Of Function ◽  
Adaptive Responses ◽  
Triple Mutant ◽  
Gain Of Function ◽  
Salt And Osmotic Stress ◽  
Plant Mutant

Ca2+ signals in plant cells are important for adaptive responses to environmental stresses. Here, we report that the Arabidopsis CATION/Ca2+ EXCHANGER2 (CCX2), encoding a putative cation/Ca2+ exchanger that localizes to the endoplasmic reticulum (ER), is strongly induced by salt and osmotic stresses. Compared with the WT, AtCCX2 loss-of-function mutant was less tolerant to osmotic stress and displayed the most noteworthy phenotypes (less root/shoot growth) during salt stress. Conversely, AtCCX2 gain-of-function mutants were more tolerant to osmotic stress. In addition, AtCCX2 partially suppresses the Ca2+ sensitivity of K667 yeast triple mutant, characterized by Ca2+ uptake deficiency. Remarkably, Cameleon Ca2+ sensors revealed that the absence of AtCCX2 activity results in decreased cytosolic and increased ER Ca2+ concentrations in comparison with both WT and the gain-of-function mutants. This was observed in both salt and nonsalt osmotic stress conditions. It appears that AtCCX2 is directly involved in the control of Ca2+ fluxes between the ER and the cytosol, which plays a key role in the ability of plants to cope with osmotic stresses. To our knowledge, Atccx2 is unique as a plant mutant to show a measured alteration in ER Ca2+ concentrations. In this study, we identified the ER-localized AtCCX2 as a pivotal player in the regulation of ER Ca2+ dynamics that heavily influence plant growth upon salt and osmotic stress.

Abstract 393: Reticulon-4B Protects Against Endoplasmic Reticulum Stress Induced Platelet Apoptosis and Hyperactivation in Diabetes

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Yan Wang ◽  
Wai Ho Tang ◽  
Xinbo Zhang ◽  
Jing Du ◽  
John Hwa ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Trafficking ◽  
Surface Expression ◽  
Diabetic Mouse ◽  
Mitochondrial Damage ◽  
Ros Production ◽  
Mitochondria Membrane Potential ◽  
Platelet Apoptosis

Background: Hyperglycemia triggered endoplasmic reticulum (ER) stress is one of the major causes for platelet hyperactivation and apoptosis in diabetes mellitus (DM). Reticulon-4B (aka Nogo-B) mainly localizes to the ER, and has been shown to influence the ER morphology, ER-Golgi trafficking, apoptotic balance, vesicle formation and protein trafficking in cells. The present study is aimed to investigate the role of Nogo-B on platelet function in DM. Methods and Results: Nogo-B is highly expressed in platelets from healthy individual. Platelets from DM patients and diabetic mice have decreased Nogo-B level. Using Streptozotocin (STZ) induced diabetic mouse model, we show that loss of Nogo (Nogo-/- mice) decreased platelet number, increased mean platelet volume and prolonged bleeding time compared to wild-type (WT) mice. Platelets from Nogo-/- mice were hyperactive with higher JONA and P-selectin surface expression compared to WT mice. Loss of Nogo increased thrombin and collagen induced platelet aggregation. Furthermore, platelets from diabetic Nogo-/- mice show elevated reactive oxygen species (ROS) production, decreased mitochondria membrane potential and increased apoptosis, which can be rescued by antioxidant N-acetyl-L-cysteine. Mechanistically, we show Nogo-B prevented sequestration of antiapoptotic proteins Bcl-xL and Bcl-2 induced by hyperglycemia, subsequently protected against platelet mitochondrial damage, ROS production, caspase-3 activation and apoptosis. Conclusion: These findings demonstrate that Nogo-B protects against ER stress induced platelet apoptosis and hyperactivation in DM by regulating Bcl-xL and Bcl-2 sequestration and mitochondrial damage. This novel pathway may provide therapeutic targets for thrombotic complications in diabetes mellitus.

Calreticulin, a multifunctional Ca2+ binding chaperone of the endoplasmic reticulum

1998 ◽  
Vol 76 (5) ◽  
pp. 779-785 ◽  
Author(s):  
Marek Michalak ◽  
Paola Mariani ◽  
Michal Opas
Keyword(s):  
Gene Expression ◽  
Endoplasmic Reticulum ◽  
Posttranslational Modification ◽  
Storage Capacity ◽  
Higher Plants ◽  
Plant Cells ◽  
Steroid Sensitive ◽  
Endoplasmic Reticulum Chaperone ◽  
Precise Role ◽  
Cellular Ca

Calreticulin is a ubiquitous endoplasmic reticulum Ca2+ binding chaperone. The protein has been implicated in a variety of diverse functions. Calreticulin is a lectin-like chaperone and, together with calnexin, it plays an important role in quality control during protein synthesis, folding, and posttranslational modification. Calreticulin binds Ca2+ and affects cellular Ca2+ homeostasis. The protein increases the Ca2+ storage capacity of the endoplasmic reticulum and modulates the function of endoplasmic reticulum Ca2+-ATPase. Calreticulin also plays a role in the control of cell adhesion and steroid-sensitive gene expression. Recently, the protein has been identified and characterized in higher plants but its precise role in plant cells awaits further investigation.Key words: calreticulin, endoplasmic reticulum, chaperone, Ca2+ binding protein.

Maintaining the permeability barrier during protein trafficking at the endoplasmic reticulum membrane

2003 ◽  
Vol 31 (6) ◽  
pp. 1227-1231 ◽  
Author(s):  
A.E. Johnson
Keyword(s):  
Endoplasmic Reticulum ◽  
Small Molecule ◽  
Protein Trafficking ◽  
Molecular Mechanisms ◽  
Protein Translocation ◽  
Cellular Membrane ◽  
Permeability Barrier ◽  
Endoplasmic Reticulum Membrane ◽  
Ion Diffusion

Many proteins are translocated across or integrated into a cellular membrane without disrupting its integrity, although it is difficult to imagine how such macromolecular transmembrane movement can occur without simultaneously allowing significant small-molecule and ion diffusion across the bilayer. Recent studies have identified some molecular mechanisms that are involved in maintaining the permeability barrier of the endoplasmic reticulum membrane during co-translational protein translocation and integration. These mechanisms are both simple and direct in concept, but are operationally complex and require the co-ordinated and regulated interaction of several multicomponent complexes.

scholarly journals Diversity and Formation of Endoplasmic Reticulum-Derived Compartments in Plants. Are These Compartments Specific to Plant Cells?: Figure 1.

2004 ◽  
Vol 136 (3) ◽  
pp. 3435-3439 ◽  
Author(s):  
Ikuko Hara-Nishimura ◽  
Ryo Matsushima ◽  
Tomoo Shimada ◽  
Mikio Nishimura
Keyword(s):  
Endoplasmic Reticulum ◽  
Plant Cells

Understanding protein trafficking in plant cells through proteomics

2005 ◽  
Vol 2 (5) ◽  
pp. 781-792 ◽  
Author(s):  
Songqin Pan ◽  
Clay J Carter ◽  
Natasha V Raikhel
Keyword(s):  
Protein Trafficking ◽  
Plant Cells
Sign in / Sign up

Export Citation Format

Share Document