scholarly journals PROTEIN SYNTHESIS AND RNA SYNTHESIS DURING MITOSIS IN ANIMAL CELLS

1963 ◽  
Vol 19 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Carol G. Konrad
Keyword(s):  
Protein Synthesis ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Animal Cells ◽  
Drastic Reduction ◽  
Human Amnion ◽  
Culture Cells ◽  
Cent Increase ◽  
Protein And Rna Synthesis ◽  
Synthetic Capacity

Protein synthesis and RNA synthesis during mitosis were studied by autoradiography on mammalian tissue culture cells. Protein synthesis was followed by incubating hamster epithelial and human amnion cells for 10 or 15 minutes with phenylalanine-C14. To study RNA synthesis the hamster cells were incubated for 10 minutes with uridine-C14. Comparisons of the synthetic capacity of the interphase and mitotic cells were then made using whole cell grain counts. The rate of RNA synthesis decreased during prophase and reached a low of 13 to 16 per cent of the average interphase rate during metaphase-anaphase. Protein synthesis in the hamster cells showed a 42 per cent increase during prophase with a subsequent return to the average interphase value during metaphase-anaphase. The human amnion cells showed no significant change at prophase but there was a 52 to 56 per cent drop in phenylalanine incorporation at metaphase-anaphase as compared to the average interphase rate. Colcemide was used on the hamster cells to study the effect of a prolonged mitotic condition on protein and RNA synthesis. Under this condition, uridine incorporation was extremely low whereas phenylalanine incorporation was still relatively high. The drastic reduction of RNA synthesis observed under mitotic conditions is believed to be due to the coiled condition of the chromosomes. The lack of a comparable reduction in protein synthesis during mitosis is interpreted as evidence for the presence in these cells of a relatively stable messenger RNA.

The effects of D- and L-threo-chloramphenicol on the early development of the chick embryo

Development ◽  
1965 ◽  
Vol 13 (3) ◽  
pp. 341-356
Author(s):  
F. S. Billett ◽  
Rosalba Collini ◽  
Louie Hamilton
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Chick Embryo ◽  
Messenger Rna ◽  
Mammalian Cells ◽  
Animal Cells ◽  
Inhibit Protein Synthesis ◽  
Acid Complex ◽  
Amino Acid Complex ◽  
Bacterial Systems

In many bacterial systems chloramphenicol has been shown to inhibit protein synthesis (Hahn & Wisseman, 1951; Gale & Folkes, 1953). The precise mechanism of this inhibition is not clear, although the evidence suggests that the interaction of the soluble RNA-amino acid complex with the ribosomes is prevented because the attachment of the messenger RNA to the ribosomes is itself impaired (Lacks & Gros, 1959; Nathans & Lipman, 1961; Jardetsky & Julian, 1964; Julian & Jardetsky, 1964). In contrast to its effect on bacterial systems, chloramphenicol has been reported to have little or no action on the protein synthesis by cell-free extracts of mammalian cells (Rendi, 1959; Ehrenstein & Lipmann, 1961). A basis for this resistance has been proposed by Vazquez (1964), who finds that whereas bacterial ribosomes bind chloramphenicol, ribosomes from other organisms do not. Nevertheless, it cannot be stated with any confidence that chloramphenicol has no effect on the protein synthesis of animal cells.

scholarly journals Specific mRNA destabilization in Dictyostelium discoideum requires RNA synthesis.

1987 ◽  
Vol 7 (12) ◽  
pp. 4585-4588 ◽  
Author(s):  
J F Amara ◽  
H F Lodish
Keyword(s):  
Protein Synthesis ◽  
Dictyostelium Discoideum ◽  
Rna Synthesis ◽  
Protein Synthesis Inhibitors ◽  
Protein And Rna Synthesis ◽  
The Common ◽  
Mrna Destabilization ◽  
Actin Protein ◽  
Specific Mrna

We tested the effects of inhibitors of protein and RNA synthesis on the disaggregation-mediated destabilization of prespore mRNAs in Dictyostelium discoideum. Incubating disaggregated cells with daunomycin to inhibit RNA synthesis prevented the loss of prespore mRNAs, whereas the inhibitor decreased or did not affect levels of the common mRNAs CZ22 and actin. Protein synthesis inhibitors varied in their effects. Cycloheximide, which inhibited protein synthesis almost completely, prevented the loss of the prespore mRNAs, but puromycin, which inhibited protein synthesis less well, did not. These results indicate that the process of specific mRNA destabilization requires the synthesis of RNA and possibly of protein.

Biotin and glucose metabolism

1970 ◽  
Vol 48 (4) ◽  
pp. 493-500 ◽  
Author(s):  
K. Dakshinamurti ◽  
L. Tarrago-Litvak ◽  
Ho Chong Hong
Keyword(s):  
Protein Synthesis ◽  
Glucose Metabolism ◽  
Pyruvate Kinase ◽  
Rna Synthesis ◽  
De Novo ◽  
Diabetic Rat ◽  
Bifunctional Enzyme ◽  
Protein And Rna Synthesis ◽  
Rat Experiments ◽  
De Novo Protein Synthesis

Biotin enhances liver glucokinase in the diabetic rat. Experiments using inhibitors of protein and RNA synthesis suggest that this is mediated through de novo protein synthesis. Biotin treatment also increases the activities of other key glycolytic kinases, phosphofructokinase and pyruvate kinase, but has no effect on a bifunctional enzyme like phosphohexose isomerase.

Introduction: virus–host interactions

1980 ◽  
Vol 210 (1180) ◽  
pp. 319-320
Keyword(s):  
Protein Synthesis ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Genetic Material ◽  
Acid Synthesis ◽  
Dna Viruses ◽  
Host Interactions ◽  
Polypeptide Sequence ◽  
Form Part ◽  
Reading Frames

Viruses are among the most extreme parasites, being almost completely dependent upon their host for their growth and replication. Having no intermediary metabolism of their own they make use of the energy supply of the host, its production of nucleoside triphosphates for nucleic acid synthesis and amino acid for protein synthesis, and all of the machinery for protein synthesis. Within the infected cell the virus competes with the host for the supply of all these things and at the same time variants compete among themselves for survival and yield of progeny. It is the intensity of this competition that has produced the most subtle and intimate interactions between virus and host. The need to fit into a protective shell imposes tight limits on the size of the genome in most classes of virus. This means that additional functions can seldom be added simply by adding the necessary genetic information unless there is a compensating loss. But by making more efficient use of the genetic material, additional functions can be accommodated without altering the size of the genome significantly. This is seen to a remarkable degree in the small DNA viruses, where segments of the genome are translated in different reading frames to give different polypeptide sequences and where multiple alternative'splicing in messenger RNA synthesis allows the same polypeptide sequence to form part of two or even three proteins with different properties.

Specific mRNA destabilization in Dictyostelium discoideum requires RNA synthesis

1987 ◽  
Vol 7 (12) ◽  
pp. 4585-4588
Author(s):  
J F Amara ◽  
H F Lodish
Keyword(s):  
Protein Synthesis ◽  
Dictyostelium Discoideum ◽  
Rna Synthesis ◽  
Protein Synthesis Inhibitors ◽  
Protein And Rna Synthesis ◽  
The Common ◽  
Mrna Destabilization ◽  
Actin Protein ◽  
Specific Mrna

We tested the effects of inhibitors of protein and RNA synthesis on the disaggregation-mediated destabilization of prespore mRNAs in Dictyostelium discoideum. Incubating disaggregated cells with daunomycin to inhibit RNA synthesis prevented the loss of prespore mRNAs, whereas the inhibitor decreased or did not affect levels of the common mRNAs CZ22 and actin. Protein synthesis inhibitors varied in their effects. Cycloheximide, which inhibited protein synthesis almost completely, prevented the loss of the prespore mRNAs, but puromycin, which inhibited protein synthesis less well, did not. These results indicate that the process of specific mRNA destabilization requires the synthesis of RNA and possibly of protein.

scholarly journals SYNTHESIS OF MESSENGER-LIKE RIBONUCLEIC ACID AND PROTEIN DURING MEIOSIS IN ISOLATED CELLS OF TRILLIUM ERECTUM

1963 ◽  
Vol 19 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Yasuo Hotta ◽  
Herbert Stern
Keyword(s):  
Messenger Rna ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Morphological Changes ◽  
Reaction Rates ◽  
Meiotic Stage ◽  
Isolated Cells ◽  
Rna Analysis ◽  
Protein And Rna Synthesis

The synthesis of RNA and protein by cultures of isolated microsporocytes has been demonstrated. The variation in capacities of such cultures to perform syntheses is a function of meiotic stage and parallels the pattern of changes observed for microsporocytes in situ. A principal feature of this pattern is the induction of syntheses during pachytene and diplotene, stages at which the chromosomes are partly contracted. By use of Actinomycin D, chloramphenicol, pulse-labeling with P32-phosphate, and nucleotide analyses of RNA digests, part of the RNA synthesized has been shown to correspond to messenger RNA. Analysis of reaction rates and the overlappings of protein and RNA synthesis indicates that the spread of cytological events in Trillium is not purely a function of the low temperature at which it occurs but, presumably, arises from a complement of regulatory devices which govern the periodic onset of reactions within the cells. The main conclusion drawn from the whole of these studies is that the sequence of morphological changes associated with chromosome contraction and movement during meiosis is accompanied by a set of gene transcriptions. Although comparatively few genes are presumed to be active during meiosis, the action of such genes may be essential to a translation of some of the information embodying the meiotic sequence which has been stored in the genome in the course of evolution.

scholarly journals RIBONUCLEIC ACID AND PROTEIN SYNTHESIS IN MITOTIC HELA CELLS

1965 ◽  
Vol 27 (3) ◽  
pp. 565-574 ◽  
Author(s):  
Terry C. Johnson ◽  
John J. Holland
Keyword(s):  
Protein Synthesis ◽  
Rna Polymerase ◽  
Hela Cells ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Mitotic Cell ◽  
Interphase Cell ◽  
Cell Extracts ◽  
Interphase Cells ◽  
Mitotic Cells

HeLa cells arrested in mitosis were obtained in large numbers, with only very slight interphase cell contamination, by employing the agitation method of Terasima and Tolmach, and Robbins and Marcus. Protein synthesis and RNA synthesis were almost completely suppressed in mitotic cells. Active polyribosomes were nearly absent in mitotic cells as compared with interphase cells treated in the same way. Cell-free protein synthesis and RNA polymerase activity were also greatly depressed in extracts of metaphase cells. The deoxyribonucleoprotein (DNP) of condensed chromosomes from mitotic cells was less efficient as a template for Escherichia coli RNA polymerase than was DNP from interphase cells, although isolated DNA from both sources was equally active as a primer. Despite very poor endogenous amino acid incorporation by extracts of metaphase cells, polyuridylate stimulated phenylalanine incorporation by a larger factor in mitotic cell extracts than it did in interphase cell extracts. These results suggest that RNA synthesis is suppressed in mitotic cells because the condensed chromosomes cannot act as a template, and that protein synthesis is depressed at least in part because messenger RNA becomes unavailable to ribosomes. This conclusion was supported by the demonstration that cells arrested in metaphase supported multiplication of normal yields of poliovirus, thereby showing that the mitotic cell is capable of considerable synthesis of RNA and protein.

Inhibition of protein synthesis by zinc: comparison between protein synthesis and RNA synthesis

1998 ◽  
Vol 17 (12) ◽  
pp. 661-667 ◽  
Author(s):  
Udo Ingbert Walther ◽  
Johannes Schulze ◽  
Wolfgang Forth
Keyword(s):  
Protein Synthesis ◽  
Rna Synthesis ◽  
A549 Cells ◽  
Zinc Toxicity ◽  
Alveolar Type ◽  
Time Curve ◽  
Synthesis Inhibition ◽  
Protein And Rna Synthesis ◽  
Rna And Protein Synthesis

Inhalation of zinc fumes may lead to the acute respiratory distress syndrome. The mechanisms of pulmonary zinc toxicity are not yet understood. Therefore we investigated zinc-dependent depression of protein and RNA synthesis in rat and human lung cell lines. 1 After exposure to 120 or 150 mmol/l zinc, RNA synthesis as assessed by uridine incorporation decreased by 60-70% between 0 and 2 h exposition in rat alveolar type II cells (L2 cells) and human fibroblast-like cells (11Lu and 16Lu cells), and by 90% between 0 and 4 h in carcinoma-derived cells (A549 cells). 2 After 2 h exposure, L2, 11Lu, and 16Lu cells were half-maximally inhibited by 50 mmol/l zinc, whereas A549 cells were more resistant with half-maximal inhibition at 100 mmol/zinc. 3 Protein and RNA synthesis was inhibited in parallel in L2, 11Lu, and A549 cells as indicated by simultaneous determination of uridine and amino acid incorporation. In 16Lu cells, the decline in protein synthesis preceded RNA synthesis inhibition. Pretreatment with RNA synthesis inhibitors (amanitin or actinomycin D) had no effect on time curve and intensity of RNA synthesis inhibition. Taken together, our results indicate that the suppression of RNA and protein synthesis likely are independent phenomena, due to direct zinc effects on these biosynthetic pathways.

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