scholarly journals Precocious germination and its regulation in embryos of triticale caryopses

2014 ◽  
Vol 56 (3) ◽  
pp. 469-483 ◽  
Author(s):  
Stanisław Weidner
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Control Sample ◽  
Precocious Germination ◽  
Mature Embryos ◽  
Triticale Caryopses ◽  
Ribosomal Protein Synthesis ◽  
Stimulation Of

Triticale var. Lasko embryos, isolated from grain gathered at milk ripeness, the beginning of wax ripeness and at full ripeness, were allowed to germinate for 48 h on agar with glucose. The highest incorporation of tritiated adenosine into polyribosomal RNA during germination was found in the ribosome fractions from embryos of grain gathered at full ripeness, lower incorporation was in preparations from embryos of milk ripe grain and the lowest in preparations from embryos of wax ripe grain. Different tendencies were observed in respect to the synthesis of ribosomal proteins. The highest incorporation of <sup>14</sup>C-amino acids into ribosomal proteins was found in preparations of ribosome fractions from embryos of milk ripe grain, lower in preparations of embryos from fully ripe grain, the lowest in preparations of embryos from wax ripe grain. ABA (10<sup>-4</sup> M) completely inhibited the external symptoms of germination of immature embryos, while its inhibition of the synthesis of polyribosomal RNA and ribosomal proteins was greater the more mature the embryos that were germinated. The greatest stimulation of precocious germination by exogenous BA and GA<sub>3</sub> was demonstrated in the least mature embryos isolated from milk ripe grain. Under the influence of both stimulators, an increase of the proportion of polyribosomes in the total ribosome fraction occurred in this sample, as did a rise in the intensity of ribosomal protein synthesis. The incorporation of <sup>3</sup>H-adenosine into polyribosomal RNA, however, was lower than in the control sample. The results obtained suggest that the regulation of precocious germination of triticale embryos by phyto-hormones is not directly related to transcription.

scholarly journals Hierarchy of elements regulating synthesis of ribosomal proteins in Saccharomyces cerevisiae.

1981 ◽  
Vol 1 (11) ◽  
pp. 1016-1023 ◽  
Author(s):  
D R Kief ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Ribonucleic Acid ◽  
Ribosomal Proteins ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Messenger Ribonucleic Acid ◽  
Ribosomal Protein Synthesis ◽  
Stimulation Of

Saccharomyces cerevisiae cells respond to a heat shock by temporarily slowing the synthesis of ribosomal proteins (C. Gorenstein and J. R. Warner, Proc. Natl. Acad. Sci. U.S.A. 73:1574-1551, 1976). When cultures growing oxidatively on ethanol as the sole carbon source were shifted from 23 to 36 degrees C, the synthesis of ribosomal proteins was coordinately inhibited twice as rapidly and 45% more severely than in comparable cultures growing fermentatively on glucose. Within 15 min, the relative rates of synthesis of at least 30 ribosomal proteins declined to less than one-sixth their initial values, whereas the overall rate of protein synthesis increased at least threefold. We suggest that this is due primarily to controls at the level of synthesis of messenger ribonucleic acid for ribosomal proteins but may also involve changes in messenger ribonucleic acid stability. In contrast, a nutritional shift-up causes a stimulation of the synthesis of ribosomal proteins. Experiments designed to determine the hierarchy of stimuli affecting the synthesis of these proteins demonstrated that temperature shock was dominant to glucose stimulation. When a culture growing on ethanol was shifted from 23 to 36 degrees C and glucose was added shortly afterward, the decline in ribosomal protein synthesis continued unabated. However, in wild-type cells ribosomal protein synthesis began to recover within 15 min. In mutants temperature sensitive for ribosome synthesis, e.g., rna2, there was no recovery in the synthesis of most ribosomal proteins, suggesting that the product of rna2 is essential for the production of these proteins under all vegetative conditions.

Hierarchy of elements regulating synthesis of ribosomal proteins in Saccharomyces cerevisiae

1981 ◽  
Vol 1 (11) ◽  
pp. 1016-1023
Author(s):  
D R Kief ◽  
J R Warner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Ribonucleic Acid ◽  
Ribosomal Proteins ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Messenger Ribonucleic Acid ◽  
Ribosomal Protein Synthesis ◽  
Stimulation Of

Saccharomyces cerevisiae cells respond to a heat shock by temporarily slowing the synthesis of ribosomal proteins (C. Gorenstein and J. R. Warner, Proc. Natl. Acad. Sci. U.S.A. 73:1574-1551, 1976). When cultures growing oxidatively on ethanol as the sole carbon source were shifted from 23 to 36 degrees C, the synthesis of ribosomal proteins was coordinately inhibited twice as rapidly and 45% more severely than in comparable cultures growing fermentatively on glucose. Within 15 min, the relative rates of synthesis of at least 30 ribosomal proteins declined to less than one-sixth their initial values, whereas the overall rate of protein synthesis increased at least threefold. We suggest that this is due primarily to controls at the level of synthesis of messenger ribonucleic acid for ribosomal proteins but may also involve changes in messenger ribonucleic acid stability. In contrast, a nutritional shift-up causes a stimulation of the synthesis of ribosomal proteins. Experiments designed to determine the hierarchy of stimuli affecting the synthesis of these proteins demonstrated that temperature shock was dominant to glucose stimulation. When a culture growing on ethanol was shifted from 23 to 36 degrees C and glucose was added shortly afterward, the decline in ribosomal protein synthesis continued unabated. However, in wild-type cells ribosomal protein synthesis began to recover within 15 min. In mutants temperature sensitive for ribosome synthesis, e.g., rna2, there was no recovery in the synthesis of most ribosomal proteins, suggesting that the product of rna2 is essential for the production of these proteins under all vegetative conditions.

scholarly journals Effect of heat shock on ribosome synthesis in Drosophila melanogaster.

1988 ◽  
Vol 8 (1) ◽  
pp. 91-95 ◽  
Author(s):  
J Bell ◽  
L Neilson ◽  
M Pellegrini
Keyword(s):  
Tissue Culture ◽  
Protein Synthesis ◽  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Ribosomal Protein Synthesis ◽  
Correct Processing

In Drosophila tissue culture cells, the synthesis of ribosomal proteins was inhibited by a 1-h 37 degrees C heat shock. Ribosomal protein synthesis was repressed to a greater extent than that of most other proteins synthesized by these cells at 25 degrees C. After a 1-h heat shock, when the cells were returned to 25 degrees C, the ribosomal proteins were much slower than most other 25 degrees C proteins to return to pre-heat shock levels of synthesis. Relative to one another, all the ribosomal proteins were inhibited and later recovered to normal levels of synthesis at the same rate and to the same extent. Unlike the ribosomal proteins, the precursor to the large rRNAs was continually synthesized during heat shock, although at a slightly reduced level, but was not processed. It was rapidly degraded, with a half-life of approximately 16 min. Pre-heat shock levels of synthesis, stability, and correct processing were restored only when ribosomal protein synthesis returned to at least 50% of that seen in non-heat-shocked cells.

scholarly journals Non-enzymatic assembly of active chimeric ribozymes from aminoacylated RNA oligonucleotides

2021 ◽  
Author(s):  
Aleksandar Radakovic ◽  
Saurja Dasgupta ◽  
Tom H Wright ◽  
Harry R.M. Aitken ◽  
Jack W Szostak
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Ribosomal Protein ◽  
Rna World ◽  
Directed Assembly ◽  
Enzymatic Function ◽  
Hammerhead Rna ◽  
Rna Backbone ◽  
Ribosomal Protein Synthesis

Aminoacylated tRNAs, which harbor a covalent linkage between amino acids and RNA, are a universally conserved feature of life. Because they are essential substrates for ribosomal translation, aminoacylated oligonucleotides must have been present in the RNA World prior to the evolution of the ribosome. One possibility we are exploring is that the aminoacyl ester linkage served another function before being recruited for ribosomal protein synthesis. The nonenzymatic assembly of ribozymes from short RNA oligomers under realistic conditions remains a key challenge in demonstrating a plausible pathway from prebiotic chemistry to the RNA World. Here, we show that aminoacylated RNAs can undergo template-directed assembly into chimeric amino acid-RNA polymers that are active ribozymes. We demonstrate that such chimeric polymers can retain the enzymatic function of their all-RNA counterparts by generating chimeric hammerhead, RNA ligase, and aminoacyl transferase ribozymes. Amino acids with diverse side chains form linkages that are well tolerated within the RNA backbone, potentially bringing novel functionalities to ribozyme catalysis. Our work suggests that aminoacylation chemistry may have played a role in primordial ribozyme assembly. Increasing the efficiency of this process provides an evolutionary rationale for the emergence of sequence and amino acid specific aminoacyl-RNA synthetase ribozymes, which could then have generated the substrates for ribosomal protein synthesis.

Regulation of Ribosomal Protein mRNA Content and Translation in Growth-Stimulated Mouse Fibroblasts

1982 ◽  
Vol 2 (6) ◽  
pp. 685-693
Author(s):  
Pamela K. Geyer ◽  
Oded Meyuhas ◽  
Robert P. Perry ◽  
Lee F. Johnson
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Growth Stimulation ◽  
Growth Conditions ◽  
Resting Cells ◽  
Serum Stimulation ◽  
Mrna Content ◽  
Ribosomal Protein Synthesis ◽  
Polyadenylated Mrna

When resting (G 0 ) mouse 3T6 fibroblasts are serum stimulated to reenter the cell cycle, the rates of synthesis of rRNA and ribosomal proteins increase, resulting in an increase in ribosome content beginning about 6 h after stimulation. In this study, we monitored the content, metabolism, and translation of ribosomal protein mRNA (rp mRNA) in resting, exponentially growing, and serum-stimulated 3T6 cells. Cloned cDNAs for seven rp mRNAs were used in DNA-excess filter hybridization studies to assay rp mRNA. We found that about 85% of rp mRNA is polyadenylated under all growth conditions. The rate of labeling of rp mRNA relative to total polyadenylated mRNA changed very little after stimulation. The half-life of rp mRNA was about 11 h in resting cells and about 8 h in exponentially growing cells, values which are similar to the half-lives of total mRNA in resting and growing cells (about 9 h). The content of rp mRNA relative to total mRNA was about the same in resting and growing 3T6 cells. Furthermore, the total amount of rp mRNA did not begin to increase until about 6 h after stimulation. Since an increase in rp mRNA content did not appear to be responsible for the increase in ribosomal protein synthesis, we determined the efficiency of translation of rp mRNA under different conditions. We found that about 85% of pulse-labeled rp mRNA was associated with polysomes in exponentially growing cells. In resting cells, however, only about half was associated with polysomes, and about 30% was found in the monosomal fraction. The distribution shifted to that found in growing cells within 3 h after serum stimulation. Similar results were obtained when cells were labeled for 10.5 h. About 70% of total polyadenylated mRNA was in the polysome fraction in all growth states regardless of labeling time, indicating that the shift in mRNA distribution was species specific. These results indicate that the content and metabolism of rp mRNA do not change significantly after growth stimulation. The rate of ribosomal protein synthesis appears to be controlled during the resting-growing transition by an alteration of the efficiency of translation of rp mRNA, possibly at the level of protein synthesis initiation.

scholarly journals Regulation of Ribosomal Protein mRNA Content and Translation in Growth-Stimulated Mouse Fibroblasts

1982 ◽  
Vol 2 (6) ◽  
pp. 685-693 ◽  
Author(s):  
Pamela K. Geyer ◽  
Oded Meyuhas ◽  
Robert P. Perry ◽  
Lee F. Johnson
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Growth Stimulation ◽  
Growth Conditions ◽  
Resting Cells ◽  
Serum Stimulation ◽  
Mrna Content ◽  
Ribosomal Protein Synthesis ◽  
Polyadenylated Mrna

When resting (G0) mouse 3T6 fibroblasts are serum stimulated to reenter the cell cycle, the rates of synthesis of rRNA and ribosomal proteins increase, resulting in an increase in ribosome content beginning about 6 h after stimulation. In this study, we monitored the content, metabolism, and translation of ribosomal protein mRNA (rp mRNA) in resting, exponentially growing, and serum-stimulated 3T6 cells. Cloned cDNAs for seven rp mRNAs were used in DNA-excess filter hybridization studies to assay rp mRNA. We found that about 85% of rp mRNA is polyadenylated under all growth conditions. The rate of labeling of rp mRNA relative to total polyadenylated mRNA changed very little after stimulation. The half-life of rp mRNA was about 11 h in resting cells and about 8 h in exponentially growing cells, values which are similar to the half-lives of total mRNA in resting and growing cells (about 9 h). The content of rp mRNA relative to total mRNA was about the same in resting and growing 3T6 cells. Furthermore, the total amount of rp mRNA did not begin to increase until about 6 h after stimulation. Since an increase in rp mRNA content did not appear to be responsible for the increase in ribosomal protein synthesis, we determined the efficiency of translation of rp mRNA under different conditions. We found that about 85% of pulse-labeled rp mRNA was associated with polysomes in exponentially growing cells. In resting cells, however, only about half was associated with polysomes, and about 30% was found in the monosomal fraction. The distribution shifted to that found in growing cells within 3 h after serum stimulation. Similar results were obtained when cells were labeled for 10.5 h. About 70% of total polyadenylated mRNA was in the polysome fraction in all growth states regardless of labeling time, indicating that the shift in mRNA distribution was species specific. These results indicate that the content and metabolism of rp mRNA do not change significantly after growth stimulation. The rate of ribosomal protein synthesis appears to be controlled during the resting-growing transition by an alteration of the efficiency of translation of rp mRNA, possibly at the level of protein synthesis initiation.

scholarly journals The use of transcription inhibitors in the study of the mechanism of abscisic acid action in germinating triticale caryopses

2014 ◽  
Vol 56 (3) ◽  
pp. 455-467 ◽  
Author(s):  
Stanisław Weidner ◽  
Włodzimierz Makowski ◽  
Andrzej Rejowski
Keyword(s):  
Protein Synthesis ◽  
Abscisic Acid ◽  
Ribosomal Proteins ◽  
Rna Synthesis ◽  
Control Sample ◽  
Low Level ◽  
Triticale Caryopses ◽  
Exogenous Aba ◽  
Early Stages ◽  
Transcription Inhibitors

The study was conducted on germinating triticale (var. Grado) caryopses. The purpose of the experiments was to compare the effect of selected inhibitors of transcription with the action of abscisic acid during germination of caryopses. The following inhibitors were used: α-amanitin, cordycepin, cycloheximide and 5-fluorouracil. Studied were the synthesis of total and polyribosomal RNA, the process of polyribosome formation and the synthesis of ribosomal proteins. The effect of exogenous ABA, especially in the early stages of germination, was not similar to any of the four above inhibitors of transcription. After 12 h of imbibition at a lowered temperature and 3 h of germination, ABA caused a relatively low level of inhibition of RNA synthesis, whereas all of the inhibitors used halted RNA synthesis in embryos by about 50-60%. After 6 h of germination, the same proportion of polyribosomes in the total ribosome fraction (46%) was found in both the embryos from the control sample and treated with ABA. The use of inhibitors brought this figure down to below 40%. The conclusion is drawn that in the early stages of germination, regulation of protein synthesis by ABA in triticale caryopses must occur on a level other than transcription.

Faster ribosome synthesis induced by elevated aortic pressure in rat heart

1987 ◽  
Vol 252 (3) ◽  
pp. C323-C327 ◽  
Author(s):  
B. H. Chua ◽  
L. A. Russo ◽  
E. E. Gordon ◽  
B. J. Kleinhans ◽  
H. E. Morgan
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Ribosomal Protein ◽  
Total Protein ◽  
Rat Heart ◽  
Relative Rate ◽  
Plasma Concentrations ◽  
Aortic Pressure ◽  
Rat Hearts ◽  
Ribosomal Protein Synthesis

An increase in aortic pressure from 60 to 120 mmHg accelerated ribosomal protein synthesis in rat hearts during 1 or 2 h of labeling with 0.4 mM [3H]phenylalanine. When hearts were perfused with buffer that contained 20 mM glucose and normal plasma concentrations of 19 other amino acids without added insulin, ribosomal protein synthesis relative to the rate of total protein synthesis increased from approximately 0.22 to 0.36 and 0.30 as aortic pressure was raised from 60 to 120 mmHg during 1 or 2 h of labeling, respectively. With the addition of insulin, the relative rate of ribosomal protein synthesis averaged 0.33 at an aortic pressure of 60 mmHg and increased to 0.42 when aortic pressure was raised to 120 mmHg. These results indicate that elevation of aortic pressure has a preferential effect on synthesis of new ribosomes. This response appears to be an early and physiologically significant event in cardiac hypertrophy.

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