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

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 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 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.

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.

scholarly journals Changes in the Endoplasmic Reticulum of Beetroot Slices During Aging

1967 ◽  
Vol 20 (6) ◽  
pp. 1063 ◽  
Author(s):  
Margaret E Jackman ◽  
RFM Van Steveninck
Keyword(s):  
Endoplasmic Reticulum ◽  
Plant Cells ◽  
Marked Change ◽  
Ion Accumulation ◽  
Ultrastructural Changes ◽  
Lamellar System ◽  
Cytoplasmic Vesicles

Ultrastructural changes occurring in beetroot parenchyma were studied from the time of cutting into disks and throughout the following 192 hr of aerated washing. The most marked change was the reduction of the endoplasmic reticulum to small cytoplasmic vesicles immediately after cutting (when leakage of ions is greatest), followed by a reorganization into lamellae (coinciding with the onset of net ion accumulation) and subsequent extension of the lamellar system. The possible relationships between these observations and others on plant cells are discussed.

scholarly journals FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE

1965 ◽  
Vol 26 (2) ◽  
pp. 523-537 ◽  
Author(s):  
G. Benjamin Bouck
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Envelope ◽  
Brown Algae ◽  
Algal Cell ◽  
Plant Cells ◽  
Membrane Systems ◽  
Two Envelopes

The structural interrelationships among several membrane systems in the cells of brown algae have been examined by electron microscopy. In the brown algae the chloroplasts are surrounded by two envelopes, the outer of which in some cases is continuous with the nuclear envelope. The pyrenoid, when present, protrudes from the chloroplast, is also surrounded by the two chloroplast envelopes, and, in addition, is capped by a third dilated envelope or "pyrenoid sac." The regular apposition of the membranes around the pyrenoid contrasts with their looser appearance over the remainder of the chloroplast. The Golgi apparatus is closely associated with the nuclear envelope in all brown algae examined, but in the Fucales this association may extend to portions of the cytoplasmic endoplasmic reticulum as well. Evidence is presented for the derivation of vesicles, characteristic of those found in the formative region of the Golgi apparatus, from portions of the underlying nuclear envelope. The possibility that a structural channeling system for carbohydrate reserves and secretory precursors may be present in brown algae is considered. Other features of the brown algal cell, such as crystal-containing bodies, the variety of darkly staining vacuoles, centrioles, and mitochondria, are examined briefly, and compared with similar structures in other plant cells.

scholarly journals Cytosolic Free N-Glycans Are Retro-Transported Into the Endoplasmic Reticulum in Plant Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Makoto Katsube ◽  
Natsuki Ebara ◽  
Megumi Maeda ◽  
Yoshinobu Kimura
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Folding ◽  
Golgi Apparatus ◽  
Plant Cells ◽  
Complex Type ◽  
Secretion Pathway ◽  
Amyloid Fibril Formation ◽  
Free Oligosaccharides ◽  
Β Amyloid ◽  
Protein Secretion Pathway

During endoplasmic reticulum (ER)-associated degradation, free N-glycans (FNGs) are produced from misfolded nascent glycoproteins via the combination of the cytosolic peptide N-glycanase (cPNGase) and endo-β-N-acetylglucosaminidase (ENGase) in the plant cytosol. The resulting high-mannose type (HMT)-FNGs, which carry one GlcNAc residue at the reducing end (GN1-FNGs), are ubiquitously found in developing plant cells. In a previous study, we found that HMT-FNGs assisted in protein folding and inhibited β-amyloid fibril formation, suggesting a possible biofunction of FNGs involved in the protein folding system. However, whether these HMT-FNGs occur in the ER, an organelle involved in protein folding, remained unclear. On the contrary, we also reported the presence of plant complex type (PCT)-GN1-FNGs, which carry the Lewisa epitope at the non-reducing end, indicating that these FNGs had been fully processed in the Golgi apparatus. Since plant ENGase was active toward HMT-N-glycans but not PCT-N-glycans that carry β1-2xylosyl and/or α1-3 fucosyl residue(s), these PCT-GN1-FNGs did not appear to be produced from fully processed glycoproteins that harbored PCT-N-glycans via ENGase activity. Interestingly, PCT-GN1-FNGs were found in the extracellular space, suggesting that HMT-GN1-FNGs formed in the cytosol might be transported back to the ER and processed in the Golgi apparatus through the protein secretion pathway. As the first step in elucidating the production mechanism of PCT-GN1-FNGs, we analyzed the structures of free oligosaccharides in plant microsomes and proved that HMT-FNGs (Man9-7GlcNAc1 and Man9-8GlcNAc2) could be found in microsomes, which almost consist of the ER compartments.

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