Seasonal pattern of glycosylation in frog liver

1991 ◽  
Vol 11 (1) ◽  
pp. 23-31
Author(s):  
S. Leoni ◽  
A. D'Alessandro ◽  
R. Conti ◽  
M. Marino ◽  
S. Spagnuolo ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Fraction ◽  
Soluble Fraction ◽  
Seasonal Pattern ◽  
Sharp Peak ◽  
Lipid Extract ◽  
Leucine Incorporation ◽  
Control Points ◽  
Summer Period ◽  
Galactosyl Transferase

The circannual behaviour of glycosylation and protein synthesis in frog liver slices was studied following the incorporation of3H-galactose and14C-glucosamine into glycolipids and glycoproteins and3H-leucine into proteins. The activity of two enzymes the galactosyl-transferase and the N-acetyl-glucosaminyl-1-P-transferase was determined. The incorporations of both sugars into the soluble fraction and into the lipid extract present a maximum during the spring-summer period. The incorporation into the protein fraction displays a different pattern:14C-Glucosamine and3H-leucine incorporation increases from winter to a maximum in autumn; the incorporation of3H-Galactose has a sharp peak during spring. The pattern of glycosyltransferase activities is similar to the pattern of incorporation of the two saccharides into proteins, indicating these enzymes as important control points for glycosylation in Anurae.

Protein synthesis and leucine uptake during fusicoccin-stimulated growth of oat coleoptile tissue

1980 ◽  
Vol 58 (22) ◽  
pp. 2356-2359 ◽  
Author(s):  
Ahmed C. Doo ◽  
Alan W. Bown
Keyword(s):  
Protein Synthesis ◽  
Indoleacetic Acid ◽  
Soluble Fraction ◽  
Leucine Incorporation ◽  
Avena Coleoptile ◽  
Total Uptake ◽  
Leucine Uptake ◽  
Significant Difference ◽  
Soluble Fractions

Avena coleoptile sections were incubated with or without cycloheximide (CHI) in solutions containing indoleacetic acid (IAA), fusicoccin (FC), or IAA and FC. Resulting growth, incorporation of [3H]leucine into protein, and uptake of [3H]leucine into an ethanol-soluble fraction were determined. FC-stimulated growth was greater and less sensitive to CHI treatment than IAA dependant growth which was virtually eliminated by CHI. IAA alone had little or no influence on [3H]leucine utilization, whereas FC treatment stimulated [3H]leucine incorporation into protein by 36% and uptake into the ethanol-soluble fraction by 75%. CHI inhibited the incorporation of [3H]leucine label into protein such that no significant difference was observed in radioactivity in protein from control, FC-, or IAA-treated tissue. However, CHI did not inhibit the FC-stimulated uptake of [3H]leucine into the ethanol soluble fraction. Total uptake of [3H]leucine obtained from the sum of radioactivities in the protein and ethanol-soluble fractions was stimulated by FC approximately 54% in the absence of CHI and 92% in the presence of CHI. IAA in combination with FC stimulated a further increase in leucine uptake. It is proposed that IAA and FC stimulate growth through processes which differ in their dependency on protein synthesis, and that FC-stimulated incorporation of label into protein results from FC-stimulated leucine uptake, not FC-stimulated protein synthesis.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Use of an in Vitro Protein Synthesizing System to Test the Mode of Action of Chloracetamides

Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Luanne M. Deal ◽  
J. T. Reeves ◽  
B. A. Larkins ◽  
F. D. Hess
Keyword(s):  
Protein Synthesis ◽  
Sand Culture ◽  
Leucine Incorporation ◽  
Insoluble Protein ◽  
In Vitro System ◽  
A Cell ◽  
Protein Incorporation ◽  
Vitro Protein

The effects of chloracetamides on protein synthesis were studied both in vivo and in vitro. Four chloracetamide herbicides, alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], CDAA (N–N-diallyl-2-chloroacetamide), and propachlor (2-chloro-N-isopropylacetanilide) were tested for inhibition of [3H]-leucine incorporation into protein. Incorporation of3H-leucine into trichloroacetic acid (TCA)-insoluble protein was inhibited in oat (Avena sativaL. ‘Victory’) seedlings grown in sand culture and treated 12 h at 1 × 10−4M with these chloracetamides. The herbicides were also tested in a cell-free protein synthesizing system containing polyribosomes purified from oat root cytoplasm. These herbicides had no effect on the rates of polypeptide elongation nor on the synthesis of specific polypeptides when herbicides (1 × 10−4M) were added directly to the system. Polypeptide formation was inhibited 89% when 1 × 10−4M cycloheximide was added during translation. Cytoplasmic polyribosomes were isolated from oat roots treated 12 h with 1 × 10−4M herbicide. Translation rates and products were not altered when these polyribosomes were added to the in vitro system. Protein synthesis is inhibited when tested in an in vivo system; however, the inhibition does not occur during the translation of mRNA into protein.

Abstract 15161: Adiponectin Exerts a Protective Role Against Vascular Remodeling During Hypertension

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Crystal M Ghantous ◽  
Sarah Hanache ◽  
Firas Kobaissy ◽  
Asad Zeidan
Keyword(s):  
Protein Synthesis ◽  
Vascular Remodeling ◽  
Mechanical Stretch ◽  
Protective Role ◽  
Leucine Incorporation ◽  
Rat Portal Vein ◽  
Length Relationship ◽  
Longitudinal Orientation ◽  
Ros Formation

Introduction: Hypertension is associated with leptin production and ROS formation in vascular smooth muscle cells (VSMC) and contributes to vascular remodeling. Adiponectin (ADQ) has a cardioprotective role on the heart, but the protective role of ADQ on VSMC during hypertension has not been fully elucidated yet. Hypothesis: Mechanical stretch/hypertension is associated with a low ADQ/leptin ratio in VSMC, leading to VSMC remodeling. Methods: To mimic hypertension, the rat portal vein was cultured either mechanically stretched with 1.2 gram weights (due to the force-length relationship normalized to the human force of stretch during hypertension and the longitudinal orientation of its VSMC) or left unstretched. ADQ, leptin, eNOS, p-ERK1/2 and p-AKT expression in VSMC was evaluated by Western blot. The protective effect of adiponectin (5-10 μg/ml; 15 min-24 hr) was investigated on ROS formation by DHE staining and on hypertrophy by protein synthesis via [ 3 H]leucine incorporation. Results: Mechanical stretch for 24 hr reduced the expression of ADQ in VSMC (0.49 ± 0.08 fold, n=6, p<0.05) and increased leptin (2.51 ± 0.39 fold, n=6, p<0.05) compared to controls. Stretch (24 hr) decreased ADQ mRNA expression by 0.31 ± 0.11 fold (n=7, p<0.05) and ADQ receptor R2 by 0.51 ± 0.21 fold (n=7, p<0.05) but had no effect on ADQ receptor R1 (n=8). This effect of stretch was associated with increased protein synthesis by 1.39 ± 0.06 fold (n=6, p<0.05), while exogenous ADQ significantly inhibited stretch-induced hypertrophy (n=6, p<0.05). Stretch (15 min) increased p-ERK1/2 and p-AKT by 2.10 ± 0.25 and 4.03 ± 0.61 fold respectively (n=5, p<0.05), but ADQ reduced p-ERK1/2 and p-AKT by 0.82 ± 0.26 and 0.55 ± 0.25 fold respectively (n=3, p<0.05) in stretched vessels. eNOS expression decreased by 0.70 ± 0.06 fold (n=5, p<0.05) after stretch for 24 hr, while ADQ increased eNOS in stretched veins by 2.02 ± 0.41 fold (n=3, p<0.05). Stretch for 1 hr increased ROS by 5.69 ± 0.13 fold (n=3, p<0.05), whereas ADQ significantly inhibited ROS in stretched vessels (1.71 ± 0.22 fold, n=3). Conclusion: Mechanical stretch reduces the ADQ/leptin ratio in VSMC. ADQ plays a protective role against vascular remodeling during hypertension by affecting eNOS, ERK, AKT, ROS and hypertrophy.

scholarly journals Stimulation of vascular protein synthesis by activation of oestrogen receptor beta

2001 ◽  
Vol 171 (3) ◽  
pp. 417-423 ◽  
Author(s):  
M Liang ◽  
E Ekblad ◽  
JA Gustafsson ◽  
BO Nilsson
Keyword(s):  
Protein Synthesis ◽  
Protein Expression ◽  
Oestrogen Receptor ◽  
Beta Agonist ◽  
Tissue Homogenate ◽  
Leucine Incorporation ◽  
Ovariectomized Mice ◽  
Sds Page ◽  
Genistein Treatment ◽  
Stimulation Of

The objective of this study was to investigate the effects of oestrogen receptor (ER) beta activation on vascular protein synthesis and protein expression. Nuclear immunoreactivity towards ER beta was observed abundantly in vascular smooth muscle and endothelial cells of mouse aorta. No ER alpha-positive cell nuclei were observed. In aorta from ovariectomized mice, treatment with the selective ER beta agonist genistein (100 nM) for 24 h increased [(3)H]leucine incorporation by about 30%. This effect was prevented by the ER blocker ICI 182780 (10 microM). Although genistein treatment stimulated protein synthesis, it caused no change in total protein determined either by the Lowry method on tissue homogenate or by densitometric scanning of protein bands (10-220 kDa) separated by SDS-PAGE. Separation of [(35)S]methionine-labelled proteins by SDS-PAGE did not reveal the protein(s) stimulated by genistein. DNA synthesis was not affected by 100 nM genistein, suggesting that genistein-induced stimulation of protein synthesis is not part of a growth response. Protein expression, determined by SDS-PAGE, was similar in aorta from ER beta-knockout and wild-type mice, suggesting that expression of vascular proteins does not depend solely on a functional ER beta gene. We suggest that activation of vascular ER beta stimulates synthesis of proteins and that this response is not associated with vascular growth.

Cycloheximide Inhibition of Cytokinin-dependent Protein Synthesis: Correlation with Betacyanin Synthesis

1983 ◽  
Vol 10 (2) ◽  
pp. 145
Author(s):  
D.C Elliott ◽  
A Koltunow
Keyword(s):  
Protein Synthesis ◽  
Biological Response ◽  
Leucine Incorporation ◽  
Basal Rate ◽  
Dependent Protein ◽  
Lag Period

Cytokinin-dependent betacyanin accumulation in Amaranthus trlcolor half-seedlings (cotyledons plus 5-mm hypocotyls) can be detected after a lag period of about 6 h. A significant (P<O.01) promotion by cytokinin of [3H]leucine incorporation into protein was observed at 5-7 h. It is concluded that the cytokinin-induced biological response was subsequent to or at the same time as the effect on protein synthesis and therefore could be dependent on it, a conclusion that is strengthened by the correlation between the effects of cycloheximide on the two processes. Cycloheximide preferentially inhibits cytokinin-dependent protein synthesis as compared to the effect of the inhibitor on the basal rate.

Stimulation of Myoblast Membrane Protein Synthesis by 25-Hydroxy-Vitamin D 3

1989 ◽  
Vol 44 (9-10) ◽  
pp. 807-812
Author(s):  
Teresita Bellido ◽  
Ricardo Boland
Keyword(s):  
Vitamin D ◽  
Protein Synthesis ◽  
Plasma Membranes ◽  
De Novo ◽  
Phosphate Uptake ◽  
Leucine Incorporation ◽  
Similar Treatment ◽  
25 Hydroxy Vitamin D ◽  
Alpha Bungarotoxin ◽  
Stimulation Of

Abstract The effects of 25-hydroxy-vitamin D3 (25 OHD3) on myoblast protein synthesis were studied in connection with its role on muscle cell phosphate metabolism . The sterol markedly increased leucine incorporation into total cell proteins in cultured chick embryo myoblasts. This enhance­ment was greater than that produced by 1,25-dihydroxy-vitamin D3 (1,25(OH)2D3) and occurred prior to a significant stimulation of cell phosphate accumulation. Maximum effects of 25 OHD3 (8 h) on myoblast phosphate uptake were suppressed by cycloheximide indicating that they are mediated by de novo protein synthesis. At a similar treatment period, labelling of myoblasts with [3H]leucine (control) and [14C]leucine (+ 25 OHD3) followed by co-electrophoresis of total protein extracts on SDS-PAGE and isoelectrofocusing gels revealed that the sterol selectively affects the synthesis of proteins of 20 kDa and 50 kDa. These macromolecules were recovered in the microsomal fraction after differential centrifugation of homogenates. Further fractionation of myoblast microsomes on sucrose density gradients show ed co-localization of the 50 kDa and 20 kDa proteins with microsomal subfractions which preferentially bind [3H -alpha]bungarotoxin, suggesting that the proteins induced by 25 OHD3 are associated to plasma membranes and may play a role in the effects of the sterol on cell phosphate uptake.

Activation of Protein Synthesis in Aging Potato Tuber Slices

1971 ◽  
Vol 26 (10) ◽  
pp. 1064-1067 ◽  
Author(s):  
Günter Kahl
Keyword(s):  
Protein Synthesis ◽  
Potato Tuber ◽  
Actinomycin D ◽  
Leucine Incorporation ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Fresh Potato ◽  
Polyuridylic Acid ◽  
Storage Organs

Whereas ribosome preparations of freshly sliced potato disks do not show appreciable activity in an in-vitro amino acid incorporation system, aging of the tissue leads to a greatly enhanced incorporation activity which reaches its maximum 24 hours after slicing. If ribosomes from freshly excised disks are provided with polyuridylic acid, their activity in the incorporation of phenylalanine is increased about 8 fold.Moreover, an RNA-fraction can be dissociated by EDTA from ribosomes of aged potato tuber slices, which sediments at 15 —18S, has a base composition different from that of 16S — rRNA, 5S-and 4S —RNA, and is not present on ribosomes of fresh slices. Its appearance is inhibited by actinomycin D and therefore most probably dependent on transcription. This compound, purified from sucrose gradients, enhances in vitro leucine incorporation into peptide material by ribosomes of fresh potato slices.The possibility is discussed that this fraction-among other factors-is responsible for the enhanced protein synthesis after slicing plant storage organs, and is indicative of a general derepression phenomenon in these tissues.

scholarly journals Tumor necrosis factor alpha induces endothelial galactosyl transferase activity and verocytotoxin receptors. Role of specific tumor necrosis factor receptors and protein kinase C

Blood ◽  
1995 ◽  
Vol 85 (3) ◽  
pp. 734-743 ◽  
Author(s):  
NC van de Kar ◽  
T Kooistra ◽  
M Vermeer ◽  
W Lesslauer ◽  
LA Monnens ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tnf Alpha ◽  
Transferase Activity ◽  
Necrosis Factor Alpha ◽  
Galactosyl Transferase ◽  
Necrosis Factor

Infections with verocytotoxin (VT) producing Escherichia coli have been strongly implicated in the epidemic form of hemolytic uremic syndrome (HUS). Endothelial damage plays a central role in the pathogenesis of HUS. In vitro studies have shown that VT can damage endothelial cells after interaction with its cellular receptor globotriaosylceramide (GbOse3cer). Cytokines, such as tumor necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) can potentiate the toxic effect of VT by inducing a protein-synthesis dependent increase in VT receptors on endothelial cells. In this study, the mechanisms underlying the increase in endothelial VT receptors induced by TNF alpha were studied in more detail. To investigate which proteins were involved in this induction, endothelial cells were incubated with and without TNF alpha in the presence of 14C-galactose or 14C-glucose. Thin-layer chromatography (TLC) analysis of the glycolipid extracts of these cells demonstrated a markedly enhanced incorporation of 14C-galactose in GbOse3cer and other galactose-containing glycolipids, suggesting that TNF alpha enhanced galactosyl-transferase activity. To examine the role of the two recently cloned TNF-receptors (TNFR-p75 and TNFR-p55) in the TNF alpha-induced increase in GbOse3cer in human endothelial cells, cells were incubated with TNF alpha, the TNFR-p55 selective R32W-S86T- TNF alpha-mutant, or the TNFR-p75 selective D143N-A145R-TNF alpha- mutant. The effect of TNF alpha activation, determined by binding- experiments with 125I-VT-1, could be largely, but not completely mimicked by R32W-S86T-TNF alpha. Although incubation of cells with D143N-A145R-TNF alpha did not show an increase in VT-1 binding, the monoclonal antibody utr-1, which prevents binding to TNFR-p75, decreased the TNF alpha-induced VT-1 binding. Activation of protein kinase C (PKC) by phorbol ester increases the expression of VT-1 receptors; this effect was prevented by the PKC inhibitor Ro31–8220 and by homologous desensitization by pretreatment with phorbol ester. In contrast, the presence of the protein kinase inhibitor Ro31–8220 or desensitization of PKC activity reduced the TNF alpha-induced increase in VT-1 receptors maximally by 50% and 24%, respectively. Comparable reductions in overall protein synthesis and the synthesis of E-selectin and plasminogen activator inhibitor-1 (PAI-1) were observed. This suggests an effect on general protein synthesis rather than a specific effect of PKC in the signal transduction pathway, by which TNF alpha induces VT-1 receptors. Our results indicate that TNF alpha can increase the VT-1 receptors on endothelial cells by inducing galactosyl- transferase activity, that this action of TNF alpha mainly occurs via the TNFR-p55; and that PKC activation increases expression of VT-1 receptors by a separate mechanism that acts additively to the TNF alpha- induced increase in VT-1 receptors.

scholarly journals THE SYNTHESIS OF ACIDIC CHROMOSOMAL PROTEINS DURING THE CELL CYCLE OF HELA S-3 CELLS

1972 ◽  
Vol 52 (2) ◽  
pp. 308-315 ◽  
Author(s):  
T. W. Borun ◽  
G. S. Stein
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Protein Fraction ◽  
Polyacrylamide Gel ◽  
Nuclear Fraction ◽  
Chromosomal Protein ◽  
Chromosomal Proteins ◽  
Kinetics Of ◽  
Mitotic Cells

The kinetics of acidic residual chromosomal protein synthesis and transport were studied throughout the cell cycle in HeLa S-3 cells synchronized by 2 mM thymidine block and selective detachment of mitotic cells. Pulse labeling the cells with leucine-3H for 2 min and then "chasing" the radioactive proteins for up to 3 hr showed that the amount of protein synthesized, transported, and retained in the acidic residual chromosomal protein fraction is greater immediately after mitosis and later in G1 than in the S or G2 phases of the cell cycle. During S, only 20–25% of the proteins synthesized and transported to the acidic residual chromosomal protein fraction are chased during the first 2 hr after pulse labeling, whereas up to 40% of the material entering the residual nuclear fraction in mitosis, G1, and G2 leaves during a 2 hr chase. Polyacrylamide gel electrophoretic profiles of these proteins, at various times after pulse labeling, reveal that the turnover of individual polypeptides within this fraction has kinetics of synthesis and turnover which are markedly different from one another and undergo stage-specific changes.

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