Analysis of the proteins in thymocyte plasma membrane and smooth endoplasmic reticulum by sodium dodecylsulfate-gel electrophoresis

1974 ◽  
Vol 332 (2) ◽  
pp. 175-191 ◽  
Author(s):  
R. Schmidt-Ullrich ◽  
E. Ferber ◽  
H. Knüfermann ◽  
H. Fischer ◽  
D.F.Hoelzl Wallach
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Gel Electrophoresis ◽  
Smooth Endoplasmic Reticulum ◽  
Sodium Dodecylsulfate

Fibrinogen Biosynthesis

1975 ◽  
Author(s):  
B. Blombach ◽  
C. Redman ◽  
B. Kudryk
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Affinity Chromatography ◽  
Gel Electrophoresis ◽  
Fibrinogen Level ◽  
Smooth Endoplasmic Reticulum ◽  
Time Intervals ◽  
Plasma Fraction ◽  
Polypeptide Chains ◽  
Dog Liver

A mixture of 3H-labeled amino acids was injected into dogs. Blood was collected at specific time intervals and fibrinogen from each corresponding plasma fraction was isolated by affinity chromatography. After reduction and alkylation, the fibrinogen chains were separated either by CM-cellulose chromatography or preparative SDS-gel electrophoresis. In one dog whose fibrinogen level was approximately 8 mg/ml, it was found that both the γ and B β chains had lower radioactivity when compared to the Aα chain, at least in the early times of appearance in blood. When this experiment was repeated in another dog whose fibrinogen level was 2 mg/ml and non-labeled amino acids were given as “chaser”, the radioactivity in the γ and Bβ chain did not reach the same value as that in the Aα chain, even after a three hour period. The significance of these findings with respect to rate of synthesis, secretion and assembly of the polypeptide chains will be discussed.Experiments were also performed using dog liver slices incubated with radioactive amino acids. Labeled, fibrinogen-related, material from detergent-solubilized rough endoplasmic reticulum (HER) could be recovered either by affinity chromatography or immunoprecipitation. Fractions were also isolated from smooth endoplasmic reticulum and Golgi. Analysis of the material isolated from BEB suggests that it may not consist of all three chains but rather one or possibly two of them to be either in degraded (during isolation procedures) or precursor form.(Supported by N.I.H. grants HL 09011–11 and AM 13620.)

scholarly journals Ultrastructural Changes in the Liver of Intravenous Heroin Addicts

2010 ◽  
Vol 10 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Goran Ilić ◽  
Radovan Karadžić ◽  
Lidija Kostić-Banović ◽  
Jovan Stojanović ◽  
Aleksandra Antović
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Liver Tissue ◽  
Smooth Endoplasmic Reticulum ◽  
Decisive Role ◽  
Basal Membrane ◽  
Ultrastructural Changes ◽  
Heroin Addicts ◽  
Transmission Electron ◽  
Ultrastructural Findings

The ultrastructural research has a decisive role in gathering the knowledge on the liver’s response to the influence of some drugs. The aim of the study was to perform an ultrastructurai analysis of the liver in chronic intravenous heroin addicts.The study involved the autopsy conducted on 40 bodies of intravenous heroin addicts and 10 control autopsies. The liver tissue was fixed in glutaraldehyde and moulded with epon for investigation purposes of ultrastructural changes. The analysis was performed using the method of transmission electron microscopy.In the group of intravenous heroin addicts, the liver autopsy samples showed degenerative vesicular and fat changes, chronic active and persistent hepatitis, cirrhosis, reduction in the amount of glycogen in hepatocytes, as well as the Kupffer cell’s dominant hypertrophy. Various changes occur in organelles, plasma membrane of hepatocytes and biliary channels as well as in the nucleus.The most important ultrastructural findings include: hyperplasia and hypertrophy of the smooth endoplasmic reticulum, which is histologically proven vesicular degeneration of hepatocyte occurring as a result of the increased synthesis of enzymes of smooth endoplasmic reticulum due to chronic intravenous heroin intake, and the presence of continuous basal membrane followed by transformation of the sinusoids into capillaries (in the cases of chronic active hepatitis and cirrhosis) which leads to a disorder of microcirculation and further progress of cirrhosis.

scholarly journals A variant of the pyroantimonate technique suitable for localization of calcium in ovarian tissue.

1979 ◽  
Vol 27 (6) ◽  
pp. 1017-1028 ◽  
Author(s):  
B S Weakley
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Lipid Droplets ◽  
Microprobe Analysis ◽  
Smooth Endoplasmic Reticulum ◽  
Ovarian Tissue ◽  
Follicle Cells ◽  
Fixation Time ◽  
X Ray ◽  
Cytoplasmic Processes

Osmium-pyroantimonate solutions for the precipitation of cations are unsuitable for use with delicate mammalian oocytes. A variant of the pyroantimonate technique employing a mixture of pyroantimonate and glutaraldehyde has been found to give successful and repeatable results if a fixation time of 4 hr is used. Calcium-containing antimonate precipitates were localized principally in nuclei, smooth endoplasmic reticulum, Golgi apparatus, mitochondria, and cytoplasmic processes of both oocytes and follicle cells, and along the plasma membrane in small oocytes. Deposits were also concentrated around the periphery of lipid droplets in the follicle cells. The presence of calcium in the precipitates was confirmed by x-ray microprobe analysis.

scholarly journals Studies on the glycosylation of hydroxylysine residues during collagen biosynthesis and the subcellular localization of collagen galactosyltransferase and collagen glucosyltransferase in tendon and cartilage cells

1975 ◽  
Vol 152 (2) ◽  
pp. 291-302 ◽  
Author(s):  
Richard Harwood ◽  
Michael E. Grant ◽  
David S. Jackson
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Specific Activity ◽  
Smooth Endoplasmic Reticulum ◽  
Gradient Centrifugation ◽  
Subcellular Fractions ◽  
Anterior Lens Capsule ◽  
Cartilage Cells ◽  
Membrane Bound ◽  
And Cartilage

1. The glycosylation of hydroxylysine during the biosynthesis of procollagen by embryonic chick tendon and cartilage cells was examined. When free and membrane-bound ribosomes isolated from cells labelled for 4min with [14C]lysine were assayed for hydroxy[14C]lysine and hydroxy[14C]lysine glycosides, it was found that hydroxylation took place only on membrane-bound ribosomes and that some synthesis of galactosylhydroxy[14C]lysine and glucosylgalactosylhydroxy[14C]lysine had occurred on the nascent peptides. 2. Assays of subcellular fractions isolated from tendon and cartilage cells labelled for 2h with [14C]lysine demonstrated that the glycosylation of procollagen polypeptides began in the rough endoplasmic reticulum. 14C-labelled polypeptides present in the smooth endoplasmic reticulum and Golgi fractions were glycosylated to extents almost identical with the respective secreted procollagens. 3. Assays specific for collagen galactosyltransferase and collagen glucosyltransferase are described, using as substrate chemically treated bovine anterior-lens-capsule collagen. 4. When homogenates were assayed for the collagen glycosyltransferase activities, addition of Triton X-100 (0.01%, w/v) was found to stimulate enzyme activities by up to 45%, suggesting that the enzymes were probably membrane-bound. 5. Assays of subcellular fractions obtained by differential centrifugation for collagen galactosyltransferase activity indicated the specific activity to be highest in the microsomal fractions. Similar results were obtained for collagen glucosyltransferase activity. 6. When submicrosomal fractions obtained by discontinuous-sucrose-density-gradient-centrifugation procedures were assayed for these enzymic activities, the collagen galactosyltransferase was found to be distributed in the approximate ratio 7:3 between rough and smooth endoplasmic reticulum of both cell types. Similar determinations of collagen glucosyltransferase indicated a distribution in the approximate ratio 3:2 between rough and smooth microsomal fractions. 7. Assays of subcellular fractions for the plasma-membrane marker 5′-nucleotidase revealed a distribution markedly different from the distributions obtained for the collagen glycosyltransferase. 8. The studies described here demonstrate that glycosylation occurs early in the intracellular processing of procollagen polypeptides rather than at the plasma membrane, as was previously suggested.

scholarly journals Subcellular localization of the enzyme that forms mannosyl retinyl phosphate from guanosine diphosphate [14C]mannose and retinyl phosphate

1979 ◽  
Vol 180 (3) ◽  
pp. 449-453 ◽  
Author(s):  
M J Smith ◽  
J B Schreiber ◽  
G Wolf
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Subcellular Localization ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Subcellular Distribution ◽  
Smooth Endoplasmic Reticulum ◽  
Marker Enzymes ◽  
Guanosine Diphosphate

The subcellular distribution of the enzyme catalysing the conversion of retinyl phosphate and GDP-[14C]mannose into [14C]mannosyl retinyl phosphate was determined by using subcellular fractions of rat liver. Purity of fractions, as determined by marker enzymes, was 80% or better. The amount of mannosyl retinyl phosphate formed (pmol/min per mg of protein) for each fraction was: rough endoplasmic reticulum 0.48 +/- 0.09 (mean +/- S.D.); smooth membranes (consisting of 60% smooth endoplasmic reticulum and 40% Golgi apparatus), 0.18 +/- 0.03; Golgi apparatus, 0.13 +/- 0.03; and plasma membrane 0.02.

Endocytosis and the lysosomal apparatus of rat Leydig cells

1984 ◽  
Vol 42 ◽  
pp. 708-709
Author(s):  
M.F. Lalli ◽  
L. Hermo ◽  
Y. Clermont
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Cell Surface ◽  
Leydig Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Extracellular Fluid ◽  
Multivesicular Bodies ◽  
Rat Testis ◽  
Endocytic Activity

The Leydig cells of the rat testis which are involved in testosterone production contain an abundance of smooth endoplasmic reticulum and mitochondria (Figs. 2,6). These cells also possess many peroxisomes, lysosomes and multivesicular bodies (MVB's). On the cell surface, the plasma membrane contains numerous short microvilli, small invaginations and large plasmalemmal folds which appear to engulf extracellular fluid. There are also many large dilated vacuoles adjacent to the cell surface. The purpose of the present study is to determine if these cells show endocytic activity and to differentiate by various cytochemical means lysosomal elements from peroxisomes.To identify lysosomes, tissue chopper sections of 2% glutaraldehyde-fixed testes (containing 2.5% dextran) were incubated in media containing thiamine monophosphate as a substrate (Lalli, 1983) to demonstrate the presence of acid phosphatase or in media containing P-nitrocatechol sulfate for the demonstration of arylsulfatase (Hopsu-Havu et al., 1967).

Control of intracellular Ca2+ activity in rat myometrium

1977 ◽  
Vol 232 (1) ◽  
pp. 50-58 ◽  
Author(s):  
R. A. Janis ◽  
D. J. Crankshaw ◽  
E. E. Daniel
Keyword(s):  
Skeletal Muscle ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Control System ◽  
Sarcoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Membrane Vesicles ◽  
High Energy ◽  
The Other ◽  
Relative Potential

Four fractions enriched, respectively, in plasma membrane (PM), smooth endoplasmic reticulum (SER), rough endoplasmic reticulum (RER), and mitochondria were isolated from estrogen-dominated rat myometrium. Ca2+ uptake by these fractions was studied in order to estimate the relative potential of the corresponding organelles for controlling intracellular Ca2+ activity. Ca2+ uptake properties of the PM, SER, and RER fractions were similar except that potentiation by oxalate was in the order RER greater than or equal SER greater than PM. However, studies with the ionophores X-537A and A23187 suggested that Ca2+ was transported into the lumen of membrane vesicles of all these fractions. Unlike that of skeletal muscle sarcoplasmic reticulum, Ca2+ uptake by the myometrial fractions was not supported by high-energy compounds other than ATP. Mitochondria took up much less Ca2+ at low, and much more Ca2+ at high, free Ca2+ concentrations than did the other fractions. The amount of Ca2+ taken up in 30 s from a 1 muM free Ca2+ solution in the presence of ATP was similar for all fractions. These results suggested that mitochondria may act as an important Ca2+ control system in rat myometrium when the intracellular Ca2+ concentration is near 1 muM or higher, whereas the PM, SER, and RER may be of major importance at Ca2+ levels of 0.3 muM or lower.

scholarly journals Differential distribution of a glucuronyltransferase, involved in glucuronoxylan synthesis, within the Golgi apparatus of pea (Pisum sativum var. Alaska)

1991 ◽  
Vol 277 (3) ◽  
pp. 653-658 ◽  
Author(s):  
M C Hobbs ◽  
M H P Delarge ◽  
E A H Baydoun ◽  
C T Brett
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Pisum Sativum ◽  
Membrane Fraction ◽  
Smooth Endoplasmic Reticulum ◽  
Subcellular Location ◽  
Sucrose Density Gradient ◽  
Differential Distribution ◽  
Golgi Stack ◽  
Golgi Membranes

The subcellular location of a glucuronyltransferase (GT) involved in glucuronoxylan synthesis in pea (Pisum sativum) has been investigated. Most of the GT activity was found in the Golgi fraction, but activity was also detected in the plasma-membrane fraction. Separation of Golgi membranes on a shallow continuous sucrose density gradient resulted in three distinct subfractions, with GT activity being confined to Golgi membranes of a density similar to that of smooth endoplasmic reticulum. The differential distribution of GT within the Golgi stack indicates that glucuronoxylan synthesis occurs in specific cisternae and that there is functional compartmentalization of the Golgi with respect to hemicellulose biosynthesis.

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