Golgi apparatus of epithelial principal cells of the epididymal initial segment of the rat: Structure, relationship with endoplasmic reticulum, and role in the formation of secretory vesicles

1991 ◽  
Vol 229 (2) ◽  
pp. 159-176 ◽  
Author(s):  
Louis Hermo ◽  
Harold Green ◽  
Yves Clermont
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Initial Segment ◽  
Secretory Vesicles ◽  
Principal Cells ◽  
Structure Relationship

scholarly journals Biosynthesis of mannosylinositolphosphoceramide in Saccharomyces cerevisiae is dependent on genes controlling the flow of secretory vesicles from the endoplasmic reticulum to the Golgi.

1991 ◽  
Vol 113 (3) ◽  
pp. 515-525 ◽  
Author(s):  
A Puoti ◽  
C Desponds ◽  
A Conzelmann
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Vesicular Transport ◽  
Metabolic Energy ◽  
Temperature Sensitive ◽  
Secretory Vesicles ◽  
Intact Cells ◽  
Alternative Models ◽  
Tentative Interpretation

Saccharomyces cerevisiae contains several abundant phosphoinositol-containing sphingolipids, namely inositolphosphoceramides (IPCs), mannosyl-inositolphosphoceramide (MIPC), which is substituted on the headgroup with an additional mannose, and M(IP)2C, a ceramide substituted with one mannose and two phosphoinositol groups. Using well-defined temperature-sensitive secretion mutants we demonstrate that the biosynthesis of MIPC, M(IP)2C, and a subclass if IPCs is dependent on genes that are required for the vesicular transport of proteins from the ER to the Golgi. Synthesis of these lipids in intact cells is dependent on metabolic energy. A likely but tentative interpretation of the data is that the biosynthesis of these sphingolipids is restricted to the Golgi apparatus, and that one or more substrates for the biosynthesis of these sphingolipids (phosphatidylinositol, IPCs, or MIPC) are delivered to the Golgi apparatus by an obligatory vesicular transport step. Alternative models to explain the data are also discussed.

Dictyosome tubules, a conspicuous membraneous system of the plant cell

1990 ◽  
Vol 48 (3) ◽  
pp. 702-703
Author(s):  
H.H. Mollenhauer ◽  
D.J. Morré
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Plant Cell ◽  
Membrane System ◽  
Coated Vesicle ◽  
Secretory Vesicles ◽  
Conspicuous Feature ◽  
Constant Diameter

Tubules of about 30 run diameter are a conspicuous feature of most, if not all, Golgi apparatus cisternae (Fig. 1). The tubules may be configured as fenestrae, networks, or single outward projections around the edges of the cisternae. Coated, vesicle-like membrane buds are a common feature of tubules. Short lengths of tubules connect secretory vesicles to cisternae.The function of the tubules is not known although they interconnect cisternae of closely spaced dictyosome stacks and have been postulated to be intermediates between endoplasmic reticulum and Golgi apparatus. Additionally, they may play a part, as yet undefined, in the movement of products between cisternae.This report demonstrates that the peripheral tubules of the Golgi apparatus are a conspicuous membrane system of the cell, equal to, and often exceeding, that of the flattened parts of the Golgi apparatus cisternae.Tubules were considered as cylinders of constant diameter with total lengths equal to the sum of all tubule segments.

scholarly journals ISOLATION OF A GOLGI APPARATUS-RICH FRACTION FROM RAT LIVER

1970 ◽  
Vol 44 (3) ◽  
pp. 484-491 ◽  
Author(s):  
D. James Morré ◽  
R. L. Hamilton ◽  
H. H. Mollenhauer ◽  
R. W. Mahley ◽  
W. P. Cunningham ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Complex Network ◽  
Rat Liver ◽  
Sucrose Gradient ◽  
Gradient Centrifugation ◽  
Rat Hepatocytes ◽  
Secretory Vesicles ◽  
Differential Centrifugation

Golgi apparatus were released without fixatives from rat hepatocytes by gentle homogenization, concentrated by differential centrifugation, and purified by sucrose gradient centrifugation. Examination of sections of purified fractions by electron microscopy showed fields of morphologically intact units of Golgi apparatus consisting of stacks of parallel flattened cisternae, secretory vesicles, and small vesicular profiles. Negative staining of unfixed pellets revealed a complex network of anastomotic tubules continuous with platelike structures and secretory vesicles. These structures corresponded, respectively, to the small vesicular profiles and parallel flattened cisternae with attached secretory vesicles of sectioned material. Small fragments of granular endoplasmic reticulum were often closely associated with the peripheral tubules, suggesting sites of continuity in intact hepatocytes.

scholarly journals Chitinase Secretion by Encysting Entamoeba invadensand Transfected Entamoeba histolytica Trophozoites: Localization of Secretory Vesicles, Endoplasmic Reticulum, and Golgi Apparatus

1999 ◽  
Vol 67 (6) ◽  
pp. 3073-3081 ◽  
Author(s):  
Sudip K. Ghosh ◽  
Jessica Field ◽  
Marta Frisardi ◽  
Benjamin Rosenthal ◽  
Zhiming Mai ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Entamoeba Histolytica ◽  
Secretory Pathway ◽  
Signal Sequence ◽  
Gene Promoter ◽  
Brefeldin A ◽  
Host Cells ◽  
Secretory Vesicles ◽  
Fluorescent Substrate

ABSTRACT Entamoeba histolytica, the protozoan parasite that phagocytoses bacteria and host cells, has a vesicle/vacuole-filled cytosol like that of macrophages. In contrast, the infectious cyst form has four nuclei and a chitin wall. Here, anti-chitinase antibodies identified hundreds of small secretory vesicles in encysting E. invadens parasites and in E. histolytica trophozoites overexpressing chitinase under an actin gene promoter. Abundant small secretory vesicles were also identified with antibodies to the surface antigen Ariel and with a fluorescent substrate of cysteine proteinases. Removal of an N-terminal signal sequence directed chitinase to the cytosol. Addition of a C-terminal KDEL peptide, identified on amebic BiP, retained chitinase in a putative endoplasmic reticulum, which was composed of a few vesicles of mixed sizes. A putative Golgi apparatus, which was Brefeldin A sensitive and composed of a few large, perinuclear vesicles, was identified with antibodies to ADP-ribosylating factor and to ɛ-COP. We conclude that the amebic secretory pathway is similar to those of other eukaryotic cells, even if its appearance is somewhat different.

Golgi Apparatus and Melanogenesis: Ultrastructural Study of a Human Cellular Blue Nevus (Melanocytoma)

1973 ◽  
Vol 31 ◽  
pp. 380-381
Author(s):  
S.R. Allegra
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Ultrastructural Study ◽  
The Other ◽  
Blue Nevus ◽  
Normal Complement ◽  
Golgi Vesicles ◽  
Golgi System ◽  
The Subject ◽  
Cellular Blue Nevus

The respective roles of the ribo somes, endoplasmic reticulum, Golgi apparatus and perhaps nucleus in the synthesis and maturation of melanosomes is still the subject of some controversy. While the early melanosomes (premelanosomes) have been frequently demonstrated to originate as Golgi vesicles, it is undeniable that these structures can be formed in cells in which Golgi system is not found. This report was prompted by the findings in an essentially amelanotic human cellular blue nevus (melanocytoma) of two distinct lines of melanocytes one of which was devoid of any trace of Golgi apparatus while the other had normal complement of this organelle.

Analysis of the Anterior Secretory Cells of Onchidohs Muricata (Nudibranchia)

1981 ◽  
Vol 39 ◽  
pp. 614-615
Author(s):  
Roy Skidmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Golgi Body ◽  
The Body ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
High Magnification ◽  
Large Numbers ◽  
Membrane Bound ◽  
Sole Of The Foot

The long-necked secretory cells in Onchidoris muricata are distributed in the anterior sole of the foot. These cells are interspersed among ciliated columnar and conical cells as well as short-necked secretory gland cells. The long-necked cells contribute a significant amount of mucoid materials to the slime on which the nudibranch travels. The body of these cells is found in the subepidermal tissues. A long process extends across the basal lamina and in between cells of the epidermis to the surface of the foot. The secretory granules travel along the process and their contents are expelled by exocytosis at the foot surface.The contents of the cell body include the nucleus, some endoplasmic reticulum, and an extensive Golgi body with large numbers of secretory vesicles (Fig. 1). The secretory vesicles are membrane bound and contain a fibrillar matrix. At high magnification the similarity of the contents in the Golgi saccules and the secretory vesicles becomes apparent (Fig. 2).

Spermatogenesis in the Dragonfly with Particular Reference to the Cytoplasmic Organelles

1972 ◽  
Vol 30 ◽  
pp. 110-111
Author(s):  
Sant S. Sekhon
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Mature Sperm ◽  
Electron Microscopic ◽  
Cytoplasmic Organelles ◽  
Microscopic Studies ◽  
Insect Sperm ◽  
Large Round

Although there have been numerous studies concerning the morphogenetic changes accompanying the maturation of insect sperm, only a few deal with the sperm differentiation in the dragonflies. In two recent electron microscopic studies Kessel, has comprehensively treated the erlationship of microtubules to the nucleus and mid-piece structures during spermiogenesis in the dragonfly. The purpose of this study is to follow the sequential nuclear and cytoplasmic changes which accompany the differentiation of spermatogonium into a mature sperm during spermatogenesis in the dragonfly (Aeschna sp.).The dragonfly spermatogonia are characterized by large round nuclei. Loosely organized chromatin is usually unevenly distributed within the spermatogonial nuclei. The scant cytoplasm surrounding the nucleus contains mitochondria, the Golgi apparatus, elements of endoplasmic reticulum and numerous ribosomes (Fig. 1).

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 Hepatic endosome fractions contain an ATP-driven proton pump

1985 ◽  
Vol 225 (1) ◽  
pp. 51-58 ◽  
Author(s):  
T Saermark ◽  
N Flint ◽  
W H Evans
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Atpase Activity ◽  
Proton Pump ◽  
Subcellular Distribution ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Ph Gradients ◽  
Subcellular Organelle ◽  
Liver Homogenates

Endosome fractions were isolated from rat liver homogenates on the basis of the subcellular distribution of circulating ligands, e.g. 125I-asialotransferrin internalized by hepatocytes by a receptor-mediated process. The distribution of endocytosed 125I-asialotransferrin 1-2 min and 15 min after uptake by liver and a monensin-activated Mg2+-dependent ATPase activity coincided on linear gradients of sucrose and Nycodenz. The monensin-activated Mg2+-ATPase was enriched relative to the liver homogenates up to 60-fold in specific activity in the endosome fractions. Contamination of the endosome fractions by lysosomes, endoplasmic reticulum, mitochondria, plasma membranes and Golgi-apparatus components was low. By use of 9-aminoacridine, a probe for pH gradients, the endosome vesicles were shown to acidify on addition of ATP. Acidification was reversed by addition of monensin. The results indicate that endosome fractions contain an ATP-driven proton pump. The ionophore-activated Mg2+-ATPase in combination with the presence of undegraded ligands in the endosome fractions emerge as linked markers for this new subcellular organelle.

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