scholarly journals NEURONAL PERIKARYA WITH DISPERSED, SINGLE RIBOSOMES IN THE VISUAL CORTEX OF MACACA MULATTA

1974 ◽  
Vol 63 (3) ◽  
pp. 1074-1089 ◽  
Author(s):  
S. L. Palay ◽  
S. Billings-Gagliardi ◽  
V. Chan-Palay
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Visual Cortex ◽  
Golgi Apparatus ◽  
Metabolic Activity ◽  
Macaca Mulatta ◽  
The Other ◽  
Cytoplasmic Matrix ◽  
Unusual Pattern ◽  
Intermediate Cells

Numerous small and medium-sized neuronal perikarya in layers III and IV of the visual cortex display an unusual pattern of ribosomal distribution. Instead of being aggregated in clusters, spirals, rows, and other regular polysomal configurations, the ribosomes, whether free or attached to the endoplasmic reticulum, are randomly dispersed, with no discernible pattern. The endoplasmic reticulum in such cells is reduced to a few (perhaps only one) meandering, broad cisternae, which delimit broad fields of cytoplasmic matrix occupied almost solely by scattered, single ribosomes. The Golgi apparatus is elaborate. Mitochondria are either small and numerous or large and infrequent. The other organelles, including the nucleus and nucleolus, are not remarkable. Axonal terminals synapse in the normal fashion on the surfaces of these cells and their dendrites. Associated with these cells are more numerous intermediate cells in which a few to many polysomal clusters can be found. It is proposed that the neurons with dispersed, single ribosomes are inactive in protein synthesis and that the suspension of such an important metabolic activity is probably temporary. Thus, these cells are considered to be part of a population undergoing cyclic fluctuations in the intensity of protein synthesis that should be correlated with their specific neural behavior.

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.

Acetylcholinesterase in Human Erythroid Cells

1973 ◽  
Vol 12 (3) ◽  
pp. 911-923
Author(s):  
R. J. SKAER
Keyword(s):  
Endoplasmic Reticulum ◽  
Nervous System ◽  
Golgi Apparatus ◽  
Red Cells ◽  
The Other ◽  
Red Cell ◽  
Erythroid Cells ◽  
Cell Replacement ◽  
Kinetics Of ◽  
Human Red Cells

Acetylcholinesterase is present in human red cells but cannot be demonstrated by the copper thiocholine test. The enzyme is revealed, however, in the perinuclear cisterna, endoplasmic reticulum and Golgi apparatus of red cell precursors. It is suggested that 2 forms of the enzyme are present, one of which can be demonstrated by the copper thiocholine test, the other cannot; one form may be the precursor of the other. These observations may cast light on the kinetics of red cell replacement and on the interpretation of the results from the copper thiocholine test on other tissues such as the nervous system.

scholarly journals Capacity of the Golgi Apparatus for Biogenesis from the Endoplasmic Reticulum

2003 ◽  
Vol 14 (12) ◽  
pp. 5011-5018 ◽  
Author(s):  
Sapna Puri ◽  
Adam D. Linstedt
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Self Assembly ◽  
De Novo ◽  
Brefeldin A ◽  
The Other ◽  
Matrix Proteins ◽  
Er Export ◽  
Golgi Matrix

It is unclear whether the mammalian Golgi apparatus can form de novo from the ER or whether it requires a preassembled Golgi matrix. As a test, we assayed Golgi reassembly after forced redistribution of Golgi matrix proteins into the ER. Two conditions were used. In one, ER redistribution was achieved using a combination of brefeldin A (BFA) to cause Golgi collapse and H89 to block ER export. Unlike brefeldin A alone, which leaves matrix proteins in relatively large remnant structures outside the ER, the addition of H89 to BFA-treated cells caused ER accumulation of all Golgi markers tested. In the other, clofibrate treatment induced ER redistribution of matrix and nonmatrix proteins. Significantly, Golgi reassembly after either treatment was robust, implying that the Golgi has the capacity to form de novo from the ER. Furthermore, matrix proteins reemerged from the ER with faster ER exit rates. This, together with the sensitivity of BFA remnants to ER export blockade, suggests that presence of matrix proteins in BFA remnants is due to cycling via the ER and preferential ER export rather than their stable assembly in a matrix outside the ER. In summary, the Golgi apparatus appears capable of efficient self-assembly.

Cytochemical studies of protein transport in the nervous system

1971 ◽  
Vol 261 (839) ◽  
pp. 407-421 ◽  
Keyword(s):  
Endoplasmic Reticulum ◽  
Nervous System ◽  
Golgi Apparatus ◽  
Metabolic Activity ◽  
Nervous Tissue ◽  
Protein Transport ◽  
Division Of Labour ◽  
Central Importance ◽  
Transport Pathways

The transport of materials within the nervous system has received much attention in recent years. Considerable information has accumulated concerning such subjects as the exchange of substances between the circulation and nervous tissue, the passage down axons of molecules and organelles originating in perikarya and the release and fate of neurotransmitters and neurosecretory agents at synapses and other neuron endings (see, for example, Wolstenholme & Porter 1968; Barondes 1969). Many investigations are underway on modulations of transport during nerve growth and regeneration and in tissue responding to injury or to other experimental alterations. However, numerous gaps remain. Of central importance to future analysis of intraneuronal transport will be the determination of details of the routes and mechanisms by which various components synthesized in the perikaryon become distributed throughout the cell. It is becoming increasingly clear that different components move along axons at quite different rates (see, for example, McEwen & Grafstein 1968). This heterogeneity may reflect the existence of a variety of intraaxonal transport pathways. Important clues derive from such work as the studies on microtubules reported by D. S. Smith in the present proceedings but much remains to be learned about possible compartmentalization of movement within axons. Similarly, the organization of perikarya must be further investigated. Neurons possess abundant rough endoplasmic reticulum, many free ribosomes, a well-developed Golgi apparatus and other features consonant with their intensive metabolic activity. Remarkably little is known, however, about most of the molecules synthesized within perikarya and about the division of labour among the organelles of the perikaryal cytoplasm.

The Ultrastructure and Histopathology of an Acidophil Adenoma of the Canine Adenohypophysis

1967 ◽  
Vol 4 (4) ◽  
pp. 348-365 ◽  
Author(s):  
C. C. Capen ◽  
S. L. Martin ◽  
A. Koestner
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Golgi Apparatus ◽  
Pancreatic Islets ◽  
Secretory Granules ◽  
Clinical Signs ◽  
Common Type ◽  
Secretory Cycle ◽  
Secretory Products ◽  
Space Occupying Lesion

An acidophil adenoma in a 12-year-old spayed boxer dog resulted in clinical signs related to a space-occupying lesion of the hypophysis. There were two types of acidophils, as determined ultrastructurally, within the adenoma. The predominating type was interpreted to be in the storage phase of the secretory cycle as the cytoplasm was densely granulated and the organelles concerned with protein synthesis and packaging of secretory products were poorly developed. The second, less common type contained few secretory granules, had a well developed endoplasmic reticulum and Golgi apparatus, and was interpreted to be secretorily active. The secretory granules of the neoplastic acidophils were large (420 m μ), uniformly electron-dense, and had a narrow submembranous space. An adenoma of the pancreatic islets was also present.

Alpha(S1)-casein is required for the efficient transport of beta- and kappa-casein from the endoplasmic reticulum to the Golgi apparatus of mammary epithelial cells

1999 ◽  
Vol 112 (19) ◽  
pp. 3399-3412 ◽  
Author(s):  
E. Chanat ◽  
P. Martin ◽  
M. Ollivier-Bousquet
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Mammary Epithelial Cells ◽  
Whey Proteins ◽  
Mammary Epithelial ◽  
The Other ◽  
Soluble Form ◽  
Beta Casein

In lactating mammary epithelial cells, interaction between caseins is believed to occur after their transport out of the endoplasmic reticulum. We show here that, in alpha(S1)-casein-deficient goats, the rate of transport of the other caseins to the Golgi apparatus is highly reduced whereas secretion of whey proteins is not significantly affected. This leads to accumulation of immature caseins in distended rough endoplasmic reticulum cisternae. Casein micelles, nevertheless, were still observed in secretory vesicles. In contrast, no accumulation was found in mammary epithelial cells which lack beta-casein. In mammary epithelial cells secreting an intermediate amount of alpha(S1)-casein, less casein accumulated in the rough endoplasmic reticulum, and the transport of alpha(S1)-casein to the Golgi occurred with kinetics similar to that of control cells. In prolactin-treated mouse mammary epithelial HC11 cells, which do not express alpha(S)-caseins, endoplasmic reticulum accumulation of beta-casein was also observed. The amount of several endoplasmic reticulum-resident proteins increased in conjunction with casein accumulation. Finally, the permeabilization of rough endoplasmic reticulum vesicles allowed the recovery of the accumulated caseins in soluble form. We conclude that optimal export of the caseins out of the endoplasmic reticulum is dependent upon alpha(S1)-casein. Our data suggest that alpha(S1)-casein interacts with the other caseins in the rough endoplasmic reticulum and that the formation of this complex is required for their efficient export to the Golgi.

scholarly journals Inhibition of Golgi Apparatus Glycosylation Causes Endoplasmic Reticulum Stress and Decreased Protein Synthesis

2010 ◽  
Vol 285 (32) ◽  
pp. 24600-24608 ◽  
Author(s):  
Yu-Xin Xu ◽  
Li Liu ◽  
Carolina E. Caffaro ◽  
Carlos B. Hirschberg
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Golgi Apparatus ◽  
Endoplasmic Reticulum Stress

scholarly journals SLC38A10 (SNAT10) is Located in ER and Golgi Compartments and Has a Role in Regulating Nascent Protein Synthesis

2019 ◽  
Vol 20 (24) ◽  
pp. 6265 ◽  
Author(s):  
Rekha Tripathi ◽  
Kimia Hosseini ◽  
Vasiliki Arapi ◽  
Robert Fredriksson ◽  
Sonchita Bagchi
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Stem Cell ◽  
Golgi Apparatus ◽  
Inhibitory Neurons ◽  
Common Substrate ◽  
Solute Carrier ◽  
Regulate Protein ◽  
Immortalized Cell

The solute carrier (SLC) family-38 of transporters has eleven members known to transport amino acids, with glutamine being a common substrate for ten of them, with SLC38A9 being the exception. In this study, we examine the subcellular localization of SNAT10 in several independent immortalized cell lines and stem cell-derived neurons. Co-localization studies confirmed the SNAT10 was specifically localized to secretory organelles. SNAT10 is expressed in both excitatory and inhibitory neurons in the mouse brain, predominantly in the endoplasmic reticulum, and in the Golgi apparatus. Knock-down experiments of SNAT10, using Slc38a10-specific siRNA in PC12 cells reduced nascent protein synthesis by more than 40%, suggesting that SNAT10 might play a role in signaling pathways that regulate protein synthesis, and may act as a transceptor in a similar fashion to what has been shown previously for SLC38A2 (SNAT2) and SNAT9(SLC38A9).

scholarly journals Intracellular localization of fibronectin by immunoelectron microscopy.

1980 ◽  
Vol 28 (9) ◽  
pp. 953-960 ◽  
Author(s):  
S S Yamada ◽  
K M Yamada ◽  
M C Willingham
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Intracellular Localization ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Protein Synthesis Inhibitors ◽  
Cultured Fibroblasts ◽  
Extracellular Glycoprotein

We have localized fibronectin, a major extracellular glycoprotein of cultured fibroblasts, in chick embryo fibroblasts at the ultrastructural level using affinity-purified antibodies to fibronectin. The use of a ferritin bridge procedure permitted quantitation of localization in various organelles. These results provide the first intracellular ultrastructural localization of fibronectin. Extracellular labeling was confined to aggregates and fibrils, with little or no labeling of the plasma membrane. The principal sites of intracellular localization were the rough endoplasmic reticulum and the Golgi apparatus. Treatment of cells with the protein synthesis inhibitors cycloheximide and pactamycin reduced fibronectin localization in the endoplasmic reticulum to 50% of normal levels. Removal of cycloheximide permitted recovery of labeling to 85% of control levels in the endoplasmic reticulum. Similar, but much reduced, changes also occurred in the Golgi apparatus.

scholarly journals Homologous Proteins of the Manganese Transporter PAM71 Are Localized in the Golgi Apparatus and Endoplasmic Reticulum

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 239 ◽  
Author(s):  
Natalie Hoecker ◽  
Anna Honke ◽  
Katharina Frey ◽  
Dario Leister ◽  
Anja Schneider
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Growth Conditions ◽  
The Other ◽  
Chloroplast Envelope ◽  
Wild Type ◽  
Homologous Proteins ◽  
Stunted Growth ◽  
Growth Defects ◽  
Precise Expression

Chloroplast manganese transporter 1 (CMT1) and photosynthesis-affected mutant 71 (PAM71) are two membrane proteins that function sequentially to mediate the passage of manganese across the chloroplast envelope and the thylakoid membrane. CMT1 and PAM71 belong to a small five-member protein family in Arabidopsis thaliana. The other three, photosynthesis-affected mutant 71 like 3 (PML3), PML4 and PML5 are not predicted to reside in chloroplast membranes. In this study, the subcellular localization of PML3:GFP, PML4:GFP and PML5:GFP was determined using transient and stable expression assays. PML3:GFP localizes to the Golgi apparatus, whereas PML4:GFP and PML5:GFP are found in the endoplasmic reticulum. We also examined patterns of PML3, PML4 and PML5 promoter activity. Although the precise expression pattern of each promoter was unique, all three genes were expressed in the leaf vasculature and in roots. Greenhouse grown single mutants pml3, pml4, pml5 and the pml4/pml5 double mutant did not exhibit growth defects, however an inspection of the root growth revealed a difference between pml3 and the other genotypes, including wild-type, in 500 µM manganese growth conditions. Strikingly, overexpression of PML3 resulted in a stunted growth phenotype. Putative functions of PML3, PML4 and PML5 are discussed in light of what is known about PAM71 and CMT1.

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