Endoplasmic Reticulum Export Sites and Golgi Bodies Behave as Single Mobile Secretory Units in Plant Cells

The ultrastructure of young growing cells of Ohara is described. The cells showed many features typical of plant cells. The nuclei of larger cells invariably contained groups of close�packed, heavily staining microtubular elements. Typical wall microtubules were always found, and large internodal cells contained filaments possibly involved in cytoplasmic streaming. Vacuolation in young internodes apparently commenced by extensive dilation of elements of the endoplasmic reticulum. In other cells, close apposition of endoplasmic reticulum to cytoplasmic inclusions indicated possible secretion of material into the organelles had been occurring. Golgi bodies with intercisternal elements were often grouped together, sometimes with interconnected cisternae. Isolated reticulate membrane systems, similar to those found at the reticulate face of golgi bodies, were sometimes seen in vacuolated cells. The golgi bodies might have been involved in vacuolation; they were also seen in association with coated vesicles that appeared to be involved in wall deposition. A large number of different cytoplasmic inclusions were found, whose nature and function is obscure. These sometimes contained crystal.like bodies.

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

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1282050.749147 ◽

2009 ◽

Author(s):

Federica Brandizzi

Keyword(s):

Endoplasmic Reticulum ◽

Laser Trapping ◽

Golgi Bodies

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0911482107 ◽

2010 ◽

Vol 107 (15) ◽

pp. 6894-6899 ◽

Cited By ~ 190

Author(s):

H. Ueda ◽

E. Yokota ◽

N. Kutsuna ◽

T. Shimada ◽

K. Tamura ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

Plant Cells ◽

Actin Organization

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The pattern of appearance of enzymic activity during the development of the Golgi apparatus in amoebae

Journal of Cell Science ◽

10.1242/jcs.34.1.53 ◽

1978 ◽

Vol 34 (1) ◽

pp. 53-63

Author(s):

C.J. Flickinger

Keyword(s):

Endoplasmic Reticulum ◽

Golgi Apparatus ◽

Rough Endoplasmic Reticulum ◽

Enzymic Activity ◽

Nuclear Transplantation ◽

Similar Distribution ◽

Cytochemical Staining ◽

Light Reaction ◽

Golgi Bodies ◽

Golgi Membranes

The appearance of enzymic activity during the development of the Golgi apparatus was studied by cytochemical staining of renucleated amoebae. In cells enucleated for 4 days, there was a great decline in size and number of Golgi bodies, or dictyosomes. Subsequent renucleation by nuclear transplantation resulted in a regeneration of Golgi bodies. Samples of amoebae were fixed and incubated for cytochemical staining at intervals of 1, 6, or 24 h after renucleation. Enzymes selected for study were guanosine diphosphatase (GDPase), esterase, and thiamine pyrophosphatase (TPPase). All three were found in the Golgi apparatus of normal amoebae but they differed in their overall intracellular distribution. GDPase was normally present at the convex pole of the Golgi apparatus, in rough endoplasmic reticulum, and in the nuclear envelope. In amoebae renucleated for 1 h, light reaction product for GDPase was present throughout the small stacks of cisternae that represented the forming Golgi apparatus. By 6 h following the operation GDPase reaction product was concentrated at the convex pole of the Golgi apparatus. Esterase, which was distributed throughout the stacks of normal Golgi cisternae, displayed a similar distribution in the forming Golgi bodies as soon as they were visible. TPPase was normally present in the Golgi apparatus but was not found in the endoplasmic reticulum. In contrast to the other enzymes, TPPase reaction product was absent from the forming Golgi apparatus 1 and 6 h after renucleation, and did not appear in the Golgi apparatus until 24 h after operation. Thus, enzymes held in common between the rough endoplasmic reticulum and the Golgi apparatus were present in the forming Golgi apparatus as soon as it was detectable, but an enzyme cytochemically localized to the Golgi apparatus only appeared later in development of the organelle. It is suggested that Golgi membranes might be derived from the endoplasmic reticulum and thus immediately contain endoplasmic reticulum enzymes, while Golgi-specific enzymes are added later in development.

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

PLANT PHYSIOLOGY ◽

10.1104/pp.106.095091 ◽

2007 ◽

Vol 143 (4) ◽

pp. 1601-1614 ◽

Cited By ~ 48

Author(s):

Myung Ki Min ◽

Soo Jin Kim ◽

Yansong Miao ◽

Juyoun Shin ◽

Liwen Jiang ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

Protein Trafficking ◽

Plant Cells

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1720422115 ◽

2018 ◽

Vol 115 (15) ◽

pp. 3966-3971 ◽

Cited By ~ 14

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.

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

Biochemistry and Cell Biology ◽

10.1139/o98-091 ◽

1998 ◽

Vol 76 (5) ◽

pp. 779-785 ◽

Cited By ~ 17

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.

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