scholarly journals Effects on protein synthesis of injecting synthetic polyribonucleotides into living cells

1974 ◽  
Vol 144 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Hugh Woodland ◽  
Sarah E. Ayers
Keyword(s):  
Protein Synthesis ◽  
Xenopus Laevis ◽  
Potent Inhibitor ◽  
Living Cells ◽  
Initiation Factor ◽  
Rna Molecules ◽  
Endogenous Protein ◽  
Limited Supply ◽  
Inhibitor Of Protein Synthesis ◽  
Haemoglobin Synthesis

Micro-injection into the oocytes and eggs of Xenopus laevis was used to ascertain the effects of synthetic polyribonucleotides on protein synthesis in living cells. Poly(U) and poly(A) were not translated detectably, nor did they change the rate of endogenous protein synthesis. The same was true of poly(G,U), poly(A,G,U), poly(A,C,G,U), G-U-G-(U)n, A-(U)n and AUG. In contrast, A-U-G-(U)n was a potent inhibitor of protein synthesis in the cell. This might be because it is initiated normally but lacks a termination codon, or because it inhibits the translation of other molecules in some way not dependent on its normal initiation. Poly(G,U), poly(A,G,U) and poly(A,C,G,U) inhibited haemoglobin synthesis when they were injected into the oocyte with haemoglobin mRNA. The synthetic polyribonucleotides did not inhibit the translation of the natural mRNA when the two sorts of molecules were injected at different times. It is suggested that the synthetic RNA molecules compete with the natural mRNA for a pre-initiation factor in limited supply.

scholarly journals Ribonuclease Activity of Rat Liver Perchloric Acid-soluble Protein, a Potent Inhibitor of Protein Synthesis

1999 ◽  
Vol 274 (29) ◽  
pp. 20688-20692 ◽  
Author(s):  
Ryo Morishita ◽  
Akihito Kawagoshi ◽  
Tatsuya Sawasaki ◽  
Kairat Madin ◽  
Tomio Ogasawara ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Rat Liver ◽  
Perchloric Acid ◽  
Soluble Protein ◽  
Potent Inhibitor ◽  
Protein A ◽  
Ribonuclease Activity ◽  
Inhibitor Of Protein Synthesis

scholarly journals Salubrinal, an inhibitor of protein synthesis, promotes deep slow wave sleep

2009 ◽  
Vol 296 (1) ◽  
pp. R178-R184 ◽  
Author(s):  
Melvi M. Methippara ◽  
Tariq Bashir ◽  
Sunil Kumar ◽  
Noor Alam ◽  
Ronald Szymusiak ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Stress Response ◽  
Er Stress ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Nrem Sleep ◽  
Initiation Factor ◽  
Er Stress Response ◽  
Intracerebroventricular Infusion ◽  
Inhibitor Of Protein Synthesis

Previous work showed that sleep is associated with increased brain protein synthesis and that arrest of protein synthesis facilitates sleep. Arrest of protein synthesis is induced during the endoplasmic reticulum (ER) stress response, through phosphorylation of eukaryotic initiation factor 2α (p-eIF2α). We tested a hypothesis that elevation of p-eIF2α would facilitate sleep. We studied the effects of intracerebroventricular infusion of salubrinal (Salub), which increases p-eIF2α by inhibiting its dephosphorylation. Salub increased deep slow wave sleep by 255%, while reducing active waking by 49%. Delta power within non-rapid eye movement (NREM) sleep was increased, while power in the sigma, beta, and gamma bands during NREM was reduced. We found that Salub increased expression of p-eIF2α in the basal forebrain (BF) area, a sleep-wake regulatory brain region. Therefore, we quantified the p-eIF2α-immunolabeled neurons in the BF area; Salub administration increased the number of p-eIF2α-expressing noncholinergic neurons in the caudal BF. In addition, Salub also increased the intensity of p-eIF2α expression in both cholinergic and noncholinergic neurons, but this was more widespread among the noncholinergic neurons. Our findings support a hypothesis that sleep is facilitated by signals associated with the ER stress response.

Characterization of protein synthesis initiation factor 2 from Xenopus laevis oocytes

Biochimie ◽  
1988 ◽  
Vol 70 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Pilar Carvallo ◽  
Mauricio G. Mateu ◽  
Jose Manuel Sierra ◽  
Jorge E. Allende
Keyword(s):  
Protein Synthesis ◽  
Xenopus Laevis ◽  
Initiation Factor ◽  
Xenopus Laevis Oocytes ◽  
Initiation Factor 2 ◽  
Protein Synthesis Initiation

scholarly journals DIFFERENT LETHAL EFFECTS OF MITOMYCIN C AND ACTINOMYCIN D DURING THE DIVISION CYCLE OF HELA CELLS

1968 ◽  
Vol 38 (3) ◽  
pp. 477-482 ◽  
Author(s):  
Bozidar Djordjevic ◽  
Jae Ho Kim
Keyword(s):  
Protein Synthesis ◽  
Mitomycin C ◽  
Hela Cells ◽  
Actinomycin D ◽  
Potent Inhibitor ◽  
S Phase ◽  
G1 Phase ◽  
Lethal Effects ◽  
Inhibitor Of Protein Synthesis

The lethal actions of mitomycin C and actinomycin D were followed during the division cycle of HeLa cells. The cells were most susceptible to a 2 hr pulse of mitomycin C during the G1 phase, whereas their sensitivity to actinomycin D was most pronounced in the S phase. Posttreatment of the cells with acetoxycycloheximide, a potent inhibitor of protein synthesis, increased the survival (colony-forming ability) of cells treated with mitomycin C but had very little effect on the survival of cells treated with actinomycin D. The significance of these findings is discussed.

scholarly journals Inhibition of protein synthesis in vitro by proteins from the seeds of Momordica charantia (bitter pear melon)

1980 ◽  
Vol 186 (2) ◽  
pp. 443-452 ◽  
Author(s):  
L Barbieri ◽  
M Zamboni ◽  
E Lorenzoni ◽  
L Montanaro ◽  
S Sperti ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Affinity Chromatography ◽  
Potent Inhibitor ◽  
Artemia Salina ◽  
Momordica Charantia ◽  
Molar Excess ◽  
Reticulocyte Lysate ◽  
Inhibitor Of Protein Synthesis ◽  
Sepharose 4B

1. A haemagglutinating lectin was purified from the seeds of Momordica charantia by affinity chromatography on Sepharose 4B and on acid-treated Sepharose 6B. It has mol.wt. 115 000 and consists of four subunits, of mol.wts. 30 500, 29 000, 28 500 and 27 000. 2. The lectin inhibits protein synthesis by a rabbit reticulocyte lysate with an ID50 (concentration giving 50% inhibition) of approx. 5 micrograms/ml. Protein synthesis by Yoshida ascites cells is partially inhibited by the lectin at a concentration of 100 micrograms/ml. 3. From the same seeds another protein was purified which has mol.wt. 23 000 and is a very potent inhibitor of protein synthesis in the lysate system, with an ID50 of 1.8 ng/ml. This inhibitor has no effect on protein synthesis by Yoshida cells, and has no haemagglutinating properties. 4. Artemia salina ribosomes preincubated with the lectin or with the inhibitor lose their capacity to perform protein synthesis. The proteins seem to act catalytically, since they inactivate a molar excess of ribosomes. 5. The lectin and the inhibitor are somewhat toxic to mice, the LD50 being 316 and 340 micrograms/100 g body wt. respectively.

scholarly journals Interaction between membrane functions and protein synthesis in reticulocytes. An elongation-stage inhibitor of protein synthesis extracted from the reticulocyte membrane

1979 ◽  
Vol 180 (2) ◽  
pp. 379-387 ◽  
Author(s):  
D H Wreschner ◽  
M Herzberg
Keyword(s):  
Protein Synthesis ◽  
Cell Membrane ◽  
High Speed ◽  
Ribosomal Subunit ◽  
Initiation Factor ◽  
Membrane Component ◽  
Initiation Complex ◽  
Initiation Factor 2 ◽  
Reticulocyte Lysate ◽  
Inhibitor Of Protein Synthesis

A component of the reticulocyte cell membrane was found to inhibit protein synthesis severely in a reticulocyte lysate system. An investigation into the mode of action of the membrane inhibitor revealed the following facts. (1) The binding of the tertiary initiation complex (methionyl-tRNAfMet-Initiation Factor 2-GTP) to the 40S ribosomal subunit was unaffected by the membrane inhibitor. (2) The membrane component did not interfere with the binding of the 40S initiation complex to the AUG initiation codon and subsequent attachment of the 60S ribosomal subunit. (3) Elongation of the peptide chain, as assayed by peptidyl-puromycin formation, was markedly affected by the membrane inhibitor. Surprisingly, the membrane component caused a considerable increase in peptidyl-puromycin formation. (4) Reticulocyte ribosomes that had been reisolated by high-speed centrifugation, after preincubation with the membrane component, were found to be highly defective when assayed in a cell-free protein-synthesizing system. These results indicated that an extract of the reticulocyte cell membrane inhibited protein synthesis by interacting with the ribosome and thus interfered with the correct functions of the elongation stage of protein synthesis. The implications of this conclusion are discussed in the light of data showing that a highly purified preparation of the membrane inhibitor also displayed an endonucleolytic activity highly specific for 28S RNA.

scholarly journals THE EFFECT OF PROTEIN SYNTHESIS INHIBITION ON THE ENTRY OF MESSENGER RNA INTO THE CYTOPLASM OF SEA URCHIN EMBRYOS

1971 ◽  
Vol 49 (3) ◽  
pp. 692-701 ◽  
Author(s):  
Brigid Hogan ◽  
Paul R. Gross
Keyword(s):  
Protein Synthesis ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Potent Inhibitor ◽  
Protein Synthesis Inhibition ◽  
Embryonic Cells ◽  
Synthesis Inhibition ◽  
Uridine Incorporation ◽  
Sea Urchin Embryos ◽  
Inhibitor Of Protein Synthesis

Emetine is a potent inhibitor of protein synthesis in sea urchin embryos. At a concentration of the drug that rapidly inhibits protein synthesis in blastulae by 95%, uridine incorporation into RNA continues for more than 1 hr and presumptive histone messenger RNA is synthesized and transported into the cytoplasm where it is apparently associated with polyribosomes. Possible explanations of this result and its implications for the "informasome" theory of messenger transport in embryonic cells are discussed.

Respiratory energy requirements and rate of protein turnover in vivo determined by the use of an inhibitor of protein synthesis and a probe to assess its effect

1994 ◽  
Vol 92 (4) ◽  
pp. 585-594 ◽  
Author(s):  
T. J. Bouma ◽  
R. De Visser ◽  
J. H. J. A. Janssen ◽  
M. J. De Kock ◽  
P H. Van Leeuwen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Energy Requirements ◽  
Inhibitor Of Protein Synthesis
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