scholarly journals The effect of kinetin on cytochemical localization of Mg++ dependent ATP-ase in isolated lupine cotyledons

2014 ◽  
Vol 50 (4) ◽  
pp. 575-581
Author(s):  
Roman Przymusiński ◽  
Adam Woźny ◽  
Fortunat Młodzianowski
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Thylakoid Membranes ◽  
Cytochemical Localization ◽  
Prolamellar Bodies

ATP-ase activity stimulated with Mg<sup>++</sup> ions was localized cytochermically in lupine cotyledons. Studies were also made of the effect of kinetin on this activity. Activity of Mg<sup>++</sup> dependent ATP-ase was observed in plasmalemma, nucleus, nucleolus, endoplasmic reticulum, thylakoid membranes, prolamellar bodies, cell wall, and irilter-cellular spaces. Kinetin (6-furfurylaminpurine) used in the experiment, stimulated ATP-ase activity, but dad not affect its localization.

scholarly journals Subcellular localization of cellulases in auxin-treated pea.

1976 ◽  
Vol 69 (1) ◽  
pp. 97-105 ◽  
Author(s):  
A K Bal ◽  
D P Verma ◽  
H Byrne ◽  
G A Maclachlan
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Major Part ◽  
Osmium Tetroxide ◽  
Close Association ◽  
Cellulase Activity ◽  
Cytochemical Localization ◽  
Tissue Sections ◽  
Inner Surface

Two forms of cellulase, buffer soluble (BS) and buffer insoluble (BI), are induced as a result of auxin treatment of dark-grown pea epicotyls. These two cellulases have been purified to homogeneity. Antibodies raised against the purified cellulases were conjugated with ferritin and were used to localize the two cellulases. Tissue sections were fixed in cold paraformaldehyde-glutaraldehyde and incubated for 1 h in the ferritin conjugates. The sections were washed with continuous shaking for 18 h and subsequently postfixed in osmium tetroxide. Tissue incubated in unconjugated ferritin was used as a control. A major part of BI cellulase is localized at the inner surface of the cell wall in close association with microfibrils. BS cellulase is localized mainly within the distended endoplasmic reticulum. Gogli complex and plasma membrane appear to be completely devoid of any cellulase activity. These observations are consistent with cytochemical localization and biochemical data on the distribution of these two cellulases among various cell and membrane fractions.

scholarly journals The Endoplasmic Reticulum and the Golgi Structures in Maize Root Cells

1959 ◽  
Vol 5 (3) ◽  
pp. 501-506 ◽  
Author(s):  
W. Gordon Whaley ◽  
Hilton H. Mollenhauer ◽  
Joyce E. Kephart
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Electron Microscope ◽  
Nuclear Envelope ◽  
Epoxy Resin ◽  
Maize Root ◽  
Root Tips ◽  
Animal Cells ◽  
Root Cells ◽  
Vesicular Structure

Maize root tips were fixed in potassium permanganate, embedded in epoxy resin, sectioned to show silver interference color, and studied with the electron microscope. All the cells were seen to contain an endoplasmic reticulum and apparently independent Golgi structures. The endoplasmic reticulum is demonstrated as a membrane-bounded, vesicular structure comparable in many aspects to that of several types of animal cells. With the treatment used here the membranes appear smooth surfaced. The endoplasmic reticulum is continuous with the nuclear envelope and, by contact at least, with structures passing through the cell wall. The nuclear envelope is characterized by discontinuities, as previously reported for animal cells. The reticula of adjacent cells seem to be in contact at or through the plasmodesmata. Because of these contacts the endoplasmic reticulum of a given cell appears to be part of an intercellular system. The Golgi structures appear as stacks of platelet-vesicles which apparently may, under certain conditions, produce small vesicles around their edges. Their form changes markedly with development of the cell.

The yeast KRE5 gene encodes a probable endoplasmic reticulum protein required for (1----6)-beta-D-glucan synthesis and normal cell growth

1990 ◽  
Vol 10 (6) ◽  
pp. 3013-3019
Author(s):  
P Meaden ◽  
K Hill ◽  
J Wagner ◽  
D Slipetz ◽  
S S Sommer ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Cell Growth ◽  
Normal Cell ◽  
Secretory Pathway ◽  
Endoplasmic Reticulum Retention Signal ◽  
Endoplasmic Reticulum Protein ◽  
Glucan Synthesis ◽  
Retention Signal ◽  
Sequential Assembly

Yeast kre mutants define a pathway of cell wall (1----6)-beta-D-glucan synthesis, and mutants in genes KRE5 and KRE6 appear to interact early in such a pathway. We have cloned KRE5, and the sequence predicts the product to be a large, hydrophilic, secretory glycoprotein which contains the COOH-terminal endoplasmic reticulum retention signal, HDEL. Deletion of the KRE5 gene resulted in cells with aberrant morphology and extremely compromised growth. Suppressors to the KRE5 deletions arose at a frequency of 1 in 10(7) to 1 in 10(8) and permitted an analysis of deletions which were found to contain no alkali-insoluble (1----6)-beta-D-glucan. These results indicate a role for (1----6)-beta-D-glucan in normal cell growth and suggest a model for sequential assembly of (1----6)-beta-D-glucan in the yeast secretory pathway.

Heterogeneity of phospholipid synthesis in rat liver endoplasmic reticulum during proliferation of smooth membranes

1976 ◽  
Vol 22 (1) ◽  
pp. 173-197
Author(s):  
J.A. Higgins
Keyword(s):  
Endoplasmic Reticulum ◽  
Uniform Distribution ◽  
Specific Activity ◽  
Intact Cell ◽  
Smooth Endoplasmic Reticulum ◽  
Membrane Phospholipid ◽  
Phospholipid Synthesis ◽  
Protein Ratio ◽  
Cytochemical Localization ◽  
Heterogeneous Distribution

During proliferation of smooth endoplasmic reticulum (SER) induced by phenobarbital the specific activity of acyltransferases of the smooth microsomes increases, there is a transient rise in the phospholipid/protein ratio of these membranes, and an increased incorporation of [14C]glycerol into smooth-membrane phospholipid. Microsomes separated into subfractions on 2 gradients exhibited a heterogeneous distribution of these characteristics, indicating a non-uniform distribution of the site of phospholipid synthesis in the ER under these conditions. Cytochemical localization of acyltransferases on whole liver and smooth and rough microsomes confirmed this heterogeneity, and indicated that the distribution of this activity was not restricted to any morphologically distinct site in the ER of the intact cell. After 4 days of phenobarbital treatment the increased membrane is restricted to lighter subfractions and is similar in distribution to that of increased acyltransferase activity. These results indicate that the synthesis of membrane phospholipid and the growth of the SER in response to phenobarbital is not uniform but occurs at randomly dispersed sites in the SER while proteins may be added preferentially at these sites resulting in a final uniform distribution.

Ultrastructural Observations of Cell Wall Regeneration Around Isolated Tobacco Protoplasts

1974 ◽  
Vol 14 (2) ◽  
pp. 439-449
Author(s):  
J. BURGESS ◽  
E. N. FLEMING
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Cell Wall Regeneration ◽  
Membrane Systems ◽  
Tobacco Protoplasts ◽  
Wall Formation ◽  
Wall Regeneration ◽  
Wall Growth

The process of cell wall regeneration around cultured protoplasts isolated from tobacco mesophyll has been examined by electron microscopy. The initially formed wall contains 2 components which stain with conventional heavy metal stains. The first consists of un-branched fibres, at first oriented at right angles to the plasmalemma surface. As wall growth proceeds the fibres lengthen and assume an orientation parallel to the plasmalemma. It seems probable that this component is cellulose. The second component of the wall is more amorphous and more densely stained. It is most frequently seen in situations where leaching of materials into the medium would be expected to be minimal. The endoplasmic reticulum and the plasmalemma are the only membrane systems which appear to contribute towards wall formation. No pattern of structure has been detected to explain the orientation or method of synthesis of the microfibrillar part of the wall.

ULTRASTRUCTURE OF THE HYPHAE AND HAUSTORIA OF PHYTOPHTHORA INFESTANS AND HYPHAE OF P. PARASITICA

1966 ◽  
Vol 44 (11) ◽  
pp. 1495-1503 ◽  
Author(s):  
Mary A. Ehrlich ◽  
Howard G. Ehrlich
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Phytophthora Infestans ◽  
Current Literature ◽  
Lipid Bodies ◽  
Potato Varieties ◽  
Parasitic Fungi ◽  
Obligate Parasites ◽  
Tubular Endoplasmic Reticulum ◽  
Cytoplasmic Continuity

The ultrastructure of the mycelium of both Phytophthora infestans and P. parasitica is consistent with that reported for other Oomycetes. A distinct plasmalemma, porate nuclei, tubular endoplasmic reticulum, mitochondria with tubular cristae, Golgi dictyosomes, and lipid bodies are present within the protoplast. The haustoria produced by P. infestans in the leaves of susceptible potato varieties consist of an expanded haustorial head surrounded by a fungus wall which is continuous with the wall of the intercellular mycelium. The haustorium lacks the long narrow stalk or neck often associated with this organ, and there is considerable cytoplasmic continuity between the haustorium and the intercellular mycelium. All P. infestans haustoria observed were anucleate and generally contained only a few mitochondria and sparse endoplasmic reticulum. The haustorium is enclosed in an encapsulation surrounded by a membrane which is continuous with the host plasmalemma. There is no evidence, around any portion of the haustorium, of a sheath originating from the cell wall of the host. A survey of the current literature on the ultrastructure of the Eumycotinia shows that the parasitic fungi exhibit no unique cytoplasmic features when compared with non-parasitic fungi, and the ultrastructure of the haustoria-producing facultative saprophyte is similar to that of the obligate parasites.

THE ORGANIZATION OF CYTOPLASMIC COMPONENTS DURING THE PHASE OF CELL WALL THICKENING IN DIFFERENTIATING CAMBIAL DERIVATIVES OF ACER RUBRUM

1965 ◽  
Vol 43 (11) ◽  
pp. 1401-1407 ◽  
Author(s):  
James Cronshaw
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Osmium Tetroxide ◽  
Acer Rubrum ◽  
Middle Layer ◽  
Wall Thickening ◽  
Cytoplasmic Microtubules ◽  
Derivatives Of ◽  
Peripheral Cytoplasm

Cambial derivatives of Acer rubrum have been examined at stages of their differentiation following fixation in 3% or 6% glutaraldehyde with a post fixation in osmium tetroxide. At early stages of development numerous free ribosomes are present in the cytoplasm, and elements of the endoplasmic reticulum tend to align themselves parallel to the cell surfaces. The plasma membrane is closely applied to the cell walls. During differentiation a complex system of cytoplasmic microtubules develops in the peripheral cytoplasm. These microtubules are oriented, mirroring the orientation of the most recently deposited microfibrils of the cell wall. The microtubules form a steep helix in the peripheral cytoplasm at the time of deposition of the middle layer of the secondary wall. During differentiation the free ribosomes disappear from the cytoplasm and numerous elements of rough endoplasmic reticulum with associated polyribosomes become more evident. In many cases the endoplasmic reticulum is associated with the cell surface. During the later stages of differentiation there are numerous inclusions between the cell wall and the plasma membrane.

scholarly journals Cytochemical localization of glucose-6-phosphatase activity in cerebral endothelial cells.

1983 ◽  
Vol 31 (6) ◽  
pp. 818-822 ◽  
Author(s):  
R D Broadwell ◽  
A M Cataldo ◽  
M Salcman
Keyword(s):  
Endothelial Cells ◽  
Endoplasmic Reticulum ◽  
Glucose Metabolism ◽  
Cell Types ◽  
Brain Parenchyma ◽  
Free Medium ◽  
Cytochemical Localization ◽  
Cerebral Endothelial Cells ◽  
G6pase Activity ◽  
Cerebral Microvasculature

Glucose-6-phosphatase (G6Pase) activity, with glucose-6-phosphate and mannose-6-phosphate as substrates, was examined by cytochemistry in capillary and arteriole endothelial cells of the mouse brain. G6Pase activity was observed ultrastructurally in the lumen of the nuclear envelope and endoplasmic reticulum (ER) of these cells. The reactive ER and nuclear membrane appeared to be in continuity. Nucleoside diphosphatase activity, also a marker for the ER in some cell types, was not seen within the ER of the cerebral microvasculature. The ER of arterioles and capillaries did not bind lead nonspecifically when incubated in a substrate-free medium. Speculation is raised concerning the involvement of G6Pase in glucose metabolism of cerebral endothelial cells and in making blood-borne glucose available to brain parenchyma.

scholarly journals Different polarisome components play distinct roles in Slt2p-regulated cortical ER inheritance in Saccharomyces cerevisiae

2013 ◽  
Vol 24 (19) ◽  
pp. 3145-3154 ◽  
Author(s):  
Xia Li ◽  
Susan Ferro-Novick ◽  
Peter Novick
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Mitogen Activated Protein Kinase ◽  
Common Mechanism ◽  
Late Step ◽  
Mitogen Activated Protein ◽  
Cortical Endoplasmic Reticulum

Ptc1p, a type 2C protein phosphatase, is required for a late step in cortical endoplasmic reticulum (cER) inheritance in Saccharomyces cerevisiae. In ptc1Δ cells, ER tubules migrate from the mother cell and contact the bud tip, yet fail to spread around the bud cortex. This defect results from the failure to inactivate a bud tip–associated pool of the cell wall integrity mitogen-activated protein kinase, Slt2p. Here we report that the polarisome complex affects cER inheritance through its effects on Slt2p, with different components playing distinct roles: Spa2p and Pea2p are required for Slt2p retention at the bud tip, whereas Bni1p, Bud6p, and Sph1p affect the level of Slt2p activation. Depolymerization of actin relieves the ptc1Δ cER inheritance defect, suggesting that in this mutant the ER becomes trapped on the cytoskeleton. Loss of Sec3p also blocks ER inheritance, and, as in ptc1Δ cells, this block is accompanied by activation of Slt2p and is reversed by depolymerization of actin. Our results point to a common mechanism for the regulation of ER inheritance in which Slt2p activity at the bud tip controls the association of the ER with the actin-based cytoskeleton.

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