scholarly journals Immunocytochemical localization of procollagen and fibronectin in human fibroblasts: effects of the monovalent ionophore, monensin.

1980 ◽  
Vol 87 (3) ◽  
pp. 663-671 ◽  
Author(s):  
P W Ledger ◽  
N Uchida ◽  
M L Tanzer
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Immunofluorescence Microscopy ◽  
Human Fibroblasts ◽  
Subsequent Development ◽  
Immunocytochemical Localization ◽  
Intracellular Accumulation ◽  
Golgi Compartment ◽  
Golgi Zone ◽  
Ionophore Monensin

The monovalent ionophore monensin inhibits the secretion of both procollagen and fibronectin from human fibroblasts in culture. The distribution of these proteins in control and inhibited (5 x 10(-7) M monensin) cells has been studied by immunofluorescence microscopy. In control cells, both antigens are present throughout the cytoplasm and in specific deposits in a region adjacent to the nucleus, which we identify as a Golgi zone by electron microscopy. Treatment of cells with monensin causes intracellular accumulation of procollagen and fibronectin, initially in the juxta-nuclear region and also subsequently in peripheral regions. Electron microscope studies reveal that in such cells the juxta-nuclear Golgi zone becomes filled with a new population of smooth-membraned vacuoles and that normal Golgi complexes are not found. Immunocytochemically detected procollagen and fibronectin are localized in the region of these vacuoles, whereas more peripheral deposits correspond to the dilated cisternae of rough endoplasmic reticulum, which are also caused by monensin. Procollagen and fibronectin are often codistributed in these peripheral deposits. Accumulation of exportable proteins in Golgi-related vacuoles is consistent with previous analyses of the monensin effect. The subsequent development of dilated rough endoplasmic reticulum also containing accumulated proteins may indicate that there is an additional blockade at the exit from the endoplasmic reticulum, or that the synthesized proteins exceed the capacity of the Golgi compartment and that their accumulation extends into the endoplasmic reticulum.

Immunocytochemical localization of wheat prolamins in the lumen of the rough endoplasmic reticulum

1991 ◽  
Vol 69 (11) ◽  
pp. 2574-2577 ◽  
Author(s):  
Hari B. Krishnan ◽  
Jerry A. White ◽  
Steven G. Pueppke
Keyword(s):  
Triticum Aestivum ◽  
Endoplasmic Reticulum ◽  
Key Words ◽  
Rough Endoplasmic Reticulum ◽  
Protein A ◽  
Triticum Aestivum L ◽  
Soluble Proteins ◽  
Immunocytochemical Localization ◽  
Specific Antibodies ◽  
Days After Anthesis

Antibodies raised against gliadins, the alcohol-soluble proteins of wheat (Triticum aestivum L.) seeds, were used to localize gliadins within the lumen of the endoplasmic reticulum. Endosperm cells at 20 days after anthesis contain extensive rough endoplasmic reticulum that is fragmented and dilated. The dilated endoplasmic reticulum encloses aggregates of proteinaceous material that reacts strongly with gliadin-specific antibodies. Key words: gliadins, immunocytochemistry, protein A – gold, rough endoplasmic reticulum, wheat.

scholarly journals Autocrine motility factor receptor is a marker for a distinct membranous tubular organelle.

1995 ◽  
Vol 129 (2) ◽  
pp. 459-471 ◽  
Author(s):  
N Benlimame ◽  
D Simard ◽  
I R Nabi
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Immunofluorescence Microscopy ◽  
Mdck Cells ◽  
Electron Microscopic ◽  
Autocrine Motility Factor ◽  
Lysosomal Fraction ◽  
Motility Factor ◽  
Variable Diameter ◽  
Triton X

Autocrine motility factor (AMF) is secreted by tumor cells and is capable of stimulating the motility of the secreting cells. In addition to being expressed on the cell surface, its receptor, AMF-R, is found within a Triton X-100 extractable intracellular tubular compartment. AMF-R tubules can be distinguished by double immunofluorescence microscopy from endosomes labeled with the transferrin receptor, lysosomes labeled with LAMP-2, and the Golgi apparatus labeled with beta-COP. AMF-R can also be separated from a LAMP-2 containing lysosomal fraction by differential centrifugation of MDCK cells and is found within a 100,000 g membrane pellet. By electron microscopic immunocytochemistry, AMF-R is localized predominantly to smooth vesicular and tubular membranous organelles as well as to a lesser extent to the plasma membrane and rough endoplasmic reticulum. AMF-R tubules have a variable diameter of 50-250 nm and can acquire an elaborate branched morphology. By immunofluorescence microscopy, AMF-R tubules are clearly distinguished from the calnexin labeled rough endoplasmic reticulum and AMF-R tubule expression is stable to extended cycloheximide treatment. The AMF-R tubule is therefore not a biosynthetic subcompartment of the endoplasmic reticulum. The tubular morphology of the AMF-R tubule is modulated by both the actin and microtubule cytoskeletons. In a similar fashion to that described previously for the tubular lysosome and endoplasmic reticulum, the linear extension and peripheral cellular orientation of the AMF-R tubule are dependent on the integrity of the microtubule cytoskeleton. The AMF-R tubule may thus form part of a family of microtubule-associated tubular organelles.

scholarly journals The rough endoplasmic reticulum and the Golgi apparatus visualized using specific antibodies in normal and tumoral prolactin cells in culture.

1983 ◽  
Vol 96 (5) ◽  
pp. 1197-1207 ◽  
Author(s):  
C Tougard ◽  
D Louvard ◽  
R Picart ◽  
A Tixier-Vidal
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Primary Cultures ◽  
Gh3 Cells ◽  
Membrane Flow ◽  
Golgi Membranes ◽  
Membrane Components ◽  
Golgi Zone

Antibodies directed against membrane components of dog pancreas rough endoplasmic reticulum (A-RER) and rat liver Golgi apparatus (A-Golgi) (Louvard, D., H. Reggio, and G. Warren, 1982, J. Cell Biol. 92:92-107) have been applied to cultured rat prolactin (PRL) cells, either normal cells in primary cultures, or clonal GH3 cells. In normal PRL cells, the A-RER stained the membranes of the perinuclear cisternae as well as those of many parallel RER cisternae. The A-Golgi stained part of the Golgi membranes. In the stacks it stained the medial saccules and, with a decreasing intensity, the saccules of the trans side, as well as, in some cells, a linear cisterna in the center of the Golgi zone. It also stained the membrane of many small vesicles as well as that of lysosomelike structures in all cells. In contrast, it never stained the secretory granule membrane, except at the level of very few segregating granules on the trans face of the Golgi zone. In GH3 cells the A-RER stained the membrane of the perinuclear cisternae, as well as that of short discontinuous flat cisternae. The A-Golgi stained the same components of the Golgi zone as in normal PRL cells. In some cells of both types the A-Golgi also stained discontinuous patches on the plasma membrane and small vesicles fusing with the plasma membrane. Immunostaining of Golgi membranes revealed modifications of membrane flow in relation to either acute stimulation of PRL release by thyroliberin or inhibition of basal secretion by monensin.

scholarly journals Yeast ER-Golgi v-SNAREs Bos1p and Bet1p differ in steady-state localization and targeting

1999 ◽  
Vol 112 (22) ◽  
pp. 4135-4142
Author(s):  
D. Ossipov ◽  
S. Schroder-Kohne ◽  
H.D. Schmitt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Cellular Localization ◽  
Immunofluorescence Microscopy ◽  
Cell Fractionation ◽  
Dependent Manner ◽  
Hybrid Proteins ◽  
Golgi Compartment ◽  
Alpha Factor ◽  
Golgi Protein

Vesicle specific SNAP receptors (v-SNAREs) Bos1p and Bet1p are involved in targeting of anterograde vesicles between the endoplasmic reticulum (ER) and early Golgi of Saccharomyces cerevisiae. To analyze factors that influence the targeting of these proteins, alpha-factor tagged versions of Bos1p and Bet1p were employed. The alpha-factor can be cleaved off by the Kex2p protease as soon as the hybrid proteins reach the late Golgi compartment. The data obtained by monitoring of Kex2p cleavage, by immunofluorescence microscopy and cell fractionation showed that Bos1-alpha and Bet1-alpha have different cellular localization and dynamics. Bos1-alpha is an ER protein, which recycles between the Golgi and the ER in COPI-dependent manner. Bet1-alpha is an early Golgi protein and it does not change its localization under conditions when other recycling Golgi proteins can be trapped in the ER.

Modification of Pineal Ultrastructure by Exogenous Hormones

1967 ◽  
Vol 25 ◽  
pp. 170-171
Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
List Type ◽  
Type Number ◽  
Pregnant Rats ◽  
Gonadal Atrophy ◽  
Pineal Ultrastructure

There have been many reports which establish a relationship between the pineal and sexual structures, including gonadal hypertrophy after pinealectomy, and gonadal atrophy after injection of pineal homogenates or of melatonin. In order to further delineate this relationship the pineals from 5 groups of female rats were studied by electron microscopy:ControlsPregnant ratsAfter 4 weekly injections of 0.1 mg. estradiol benzoate.After 8 daily injections of 150 mcgm. melatonin (pineal hormone).After 8 daily injections of 3 mg. serotonin (melatonin precursor).No ultrastructural differences were evident between the control, and the pregnancy and melatonin groups. However, the estradiol injected animals exhibited a marked increase in the amount and size of rough endoplasmic reticulum within the pineal cells.

Membrane-associated microtubular areays induced in proximal myelinated processes of dorsal root ganglia by large doses of vitamin B6

1986 ◽  
Vol 44 ◽  
pp. 368-369
Author(s):  
V.J. Montpetit ◽  
S. Dancea ◽  
L. Tryphonas ◽  
D.F. Clapin
Keyword(s):  
Animal Model ◽  
Endoplasmic Reticulum ◽  
Dorsal Root Ganglia ◽  
Rough Endoplasmic Reticulum ◽  
Dorsal Root ◽  
Vitamin B6 ◽  
Morphological Changes ◽  
Model System ◽  
Sensory Nerves ◽  
Peripheral Sensory

Very large doses of pyridoxine (vitamin B6) are neurotoxic in humans, selectively affecting the peripheral sensory nerves. We have undertaken a study of the morphological and biochemical aspects of pyridoxine neurotoxicity in an animal model system. Early morphological changes in dorsal root ganglia (DRG) associated with pyridoxine megadoses include proliferation of neurofilaments, ribosomes, rough endoplasmic reticulum, and Golgi complexes. We present in this report evidence of the formation of unique aggregates of microtubules and membranes in the proximal processes of DRG which are induced by high levels of pyridoxine.

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