De novo protein synthesis and protein phosphorylation during anoxia and recovery in the red-eared turtle

1993 ◽  
Vol 265 (6) ◽  
pp. R1380-R1386 ◽  
Author(s):  
S. P. Brooks ◽  
K. B. Storey

Changes in de novo protein synthesis and protein phosphorylation were monitored during anoxia and recovery in the red-eared slider Trachemys (= Pseudemys) scripta elegans. Time courses of 35S-radiolabeled methionine incorporation into acid-precipitable material showed an increase up to 5 h postinjection and remained constant after this time. Comparison of the total and acid-precipitable 35S label incorporation into tissues from 20-h control, anoxic, and recovering animals showed differences between these groups: total radioactivity in brain was 2.9-fold lower in recovering turtles, whereas protein-associated radioactivity was 2.4-fold higher in anoxic liver, 2.3-fold lower in recovering skeletal muscle, and 3.7-fold lower in recovering brain tissue. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radiolabeled proteins showed the existence of a newly synthesized protein band (relative molecular mass = 72 kDa) that was apparent only in 20-h recovering liver and skeletal muscle. Use of 32P labeling to monitor changes in protein phosphorylation patterns during anoxia revealed 1.6-, 1.4-, and 1.5-fold increases in 32P incorporation in anoxic brain, heart, and liver, respectively. Changes in protein phosphorylation were localized to the plasma membrane and cytosolic fractions in brain and to the cytosolic fraction in liver.

1977 ◽  
Vol 162 (2) ◽  
pp. 341-346 ◽  
Author(s):  
F H A Janszen ◽  
B A Cooke ◽  
H J van der Molen

The effect of luteinizing hormone (luteotropin) and cycloheximide on specific protein synthesis in rat testis Leydig cells has been investigated. Proteins were labelled with either I114C]leucine, [3H]leucine or [35S]methionine during incubation with Leydig-cell suspensions in vitro. Total protein was extracted from the cells and separated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. No detectable increase in the synthesis of specific proteins could be observed after incubation of Leydig cells with luteinizing hormone for up to 1 h. However, after a 2h incubation period, an increase in [35S]methionine incorporation was observed in a protein with an apparent mol.wt. of 21000 (referred to as ‘protein 21’). When, after labelling of this protein with [35S]-methionine, Leydig cells were incubated for another 30min with cycloheximide, no decrease in radioactivity of this protein band was observed, indicating that it does not have a short half-life. However, another protein band was detected, which after incubation with cycloheximide disappeared rapidly, the reaction following first-order kinetics, with a half-life of about 11 min. This protein, with an apparent mol.wt. of 33000 (referred to as “protein 33”), was found to be located in the particulate fraction of the Leydig cell, and could not be demonstrated in other rat testis-cell types or blood cells. No effect of luteinizing hormone on molecular weight, subcellular localization or half-life of protein 33 was observed. A possible role for protein 33 and protein 21 in the mechanism of action of luteinizing hormone on testosterone production of Leydig cells is discussed.


2002 ◽  
Vol 76 (15) ◽  
pp. 7578-7586 ◽  
Author(s):  
Bodil Øster ◽  
Per Höllsberg

ABSTRACT Herpesvirus gene expression is divided into immediate-early (IE) or α genes, early (E) or β genes, and late (L) or γ genes on the basis of temporal expression and dependency on other gene products. By using real-time PCR, we have investigated the expression of 35 human herpesvirus 6B (HHV-6B) genes in T cells infected by strain PL-1. Kinetic analysis and dependency on de novo protein synthesis and viral DNA polymerase activity suggest that the HHV-6B genes segregate into six separate kinetic groups. The genes expressed early (groups I and II) and late (groups V and VI) corresponded well with IE and L genes, whereas the intermediate groups III and IV contained E and L genes. Although HHV-6B has characteristics similar to those of other roseoloviruses in its overall gene regulation, we detected three B-variant-specific IE genes. Moreover, genes that were independent of de novo protein synthesis clustered in an area of the viral genome that has the lowest identity to the HHV-6A variant. The organization of IE genes in an area of the genome that differs from that of HHV-6A underscores the distinct differences between HHV-6B and HHV-6A and may provide a basis for further molecular and immunological analyses to elucidate their different biological behaviors.


2004 ◽  
Vol 31 (8) ◽  
pp. 847 ◽  
Author(s):  
Tae-Hwan Kim ◽  
Bok-Rye Lee ◽  
Woo-Jin Jung ◽  
Kil-Yong Kim ◽  
Jean-Christophe Avice ◽  
...  

The kinetics of protein incorporation from newly-absorbed nitrogen (N, de novo protein synthesis) was estimated by 15N tracing in 18-week-old white clover plants (Trifolium repens L. cv. Regal) during 7 d of water-deficit treatment. The physiological relationship between kinetics and accumulation of proline and ammonia in response to the change in leaf-water parameters was also assessed. All leaf-water parameters measured decreased gradually under water deficit. Leaf and root dry mass was not significantly affected during the first 3 d when decreases in leaf-water parameters were substantial. However, metabolic parameters such as total N, proline and ammonia were significantly affected within 1 d of commencement of water-deficit treatment. Water-deficit treatment significantly increased the proline and NH3–NH4+ concentrations in both leaves and roots. There was a marked reduction in the amount of N incorporated into the protein fraction from the newly absorbed N (NANP) in water-deficit stressed plants, particularly in leaf tissue. This reduction in NANP was strongly associated with an increased concentration of NH3–NH4+ in roots (P≤0.05) and proline (P≤0.01) in leaves and roots. These results suggest that proline accumulation may be a sensitive biochemical indicator of plant water status and of the dynamics of de novo protein synthesis in response to stress severity.


2007 ◽  
Vol 73 (7) ◽  
pp. 2247-2250 ◽  
Author(s):  
Sirinat Srionnual ◽  
Fujitoshi Yanagida ◽  
Li-Hsiu Lin ◽  
Kuang-Nan Hsiao ◽  
Yi-sheng Chen

ABSTRACT Weissella cibaria 110, isolated from the Thai fermented fish product plaa-som, was found to produce a bacteriocin active against some gram-positive bacteria. Bacteriocin activity was not eliminated by exposure to high temperatures or catalase but was destroyed by exposure to the proteolytic enzymes proteinase K and trypsin. The bacteriocin from W. cibaria 110 was purified, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the purified bacteriocin contained one protein band that was approximately 2.5 kDa in size. Mass spectrometry analysis showed the mass of the peptide to be approximately 3,487.8 Da. N-terminal amino acid sequence analysis was performed, and 27 amino acids were identified. Because it has no similarity to other known bacteriocins, this bacteriocin was defined as a new bacteriocin and termed weissellicin 110.


Author(s):  
Margarita Elena Papandreou ◽  
Konstantinos Palikaras ◽  
Nektarios Tavernarakis

2002 ◽  
Vol 87 (04) ◽  
pp. 674-683 ◽  
Author(s):  
John Martens ◽  
Lambert Dorssers ◽  
Jan Klijn ◽  
John Foekens ◽  
Anieta Sieuwerts

SummaryIn breast stroma urokinase plasminogen activator (uPA) is predominantly expressed by fibroblasts located in the near vicinity of tumor cells, and fibroblast-derived insulin-like growth factor-1 (IGF-1) may be involved in inhibiting the expression of uPA in these fibroblasts. To investigate a possible role for fibroblast growth factors (FGFs), we evaluated the expression of components of the PA system and the IGF system in normal and tumor-tissue-derived human breast fibroblasts exposed to various FGFs in vitro. mRNA analysis revealed that FGF-1, FGF-2 and FGF-4 induced the mRNA expression levels of uPA, tPA, uPAR, PAI-1 and PAI-2, and reduced those of IGF-1, IGF-1R, IGF-2R and IGFBP-4, without significantly affecting the levels of IGFBP-3, IGFBP-5 and IGFBP-6 mRNA. Concerning the expression of IGF-2 mRNA, the effects mediated by FGF-1, FGF-2 and FGF-4 were divergent. In general, the effects elicited by FGF-1 on the various mRNA levels studied were rapid and short-term. Those mediated by FGF-2 overall lagged behind but were longer-lasting. For FGF-4 an in between pattern was observed. Blocking transcription and translation demonstrated that a) both the FGF-1 and FGF-2 induced effects were the result of altered gene transcription or mRNA stability, b) the short-term effects mediated by FGF-1 and FGF-2 required de novo protein synthesis, and c) the long-term effects elicited by FGF-2 did not depend on de novo protein synthesis during the first 24 h, but were triggered by proteins produced or made available thereafter. The data presented propose that of the FGFs studied (FGF-1, -2, -4, -5, and -7), FGF-2 is the most attractive target for therapeutical strategies aimed at diminishing the contribution of stromal fibroblasts in the PA-directed breast tumor proteolysis.


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