scholarly journals Ricin - a potent inhibitor of protein synthesis

FEBS Letters ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 327-329 ◽  
Author(s):  
S. Olsnes ◽  
A. Pihl
1974 ◽  
Vol 144 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Hugh Woodland ◽  
Sarah E. Ayers

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.


1999 ◽  
Vol 274 (29) ◽  
pp. 20688-20692 ◽  
Author(s):  
Ryo Morishita ◽  
Akihito Kawagoshi ◽  
Tatsuya Sawasaki ◽  
Kairat Madin ◽  
Tomio Ogasawara ◽  
...  

1968 ◽  
Vol 38 (3) ◽  
pp. 477-482 ◽  
Author(s):  
Bozidar Djordjevic ◽  
Jae Ho Kim

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.


1980 ◽  
Vol 186 (2) ◽  
pp. 443-452 ◽  
Author(s):  
L Barbieri ◽  
M Zamboni ◽  
E Lorenzoni ◽  
L Montanaro ◽  
S Sperti ◽  
...  

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.


1971 ◽  
Vol 49 (3) ◽  
pp. 692-701 ◽  
Author(s):  
Brigid Hogan ◽  
Paul R. Gross

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.


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 ◽  
...  

1993 ◽  
Vol 268 (33) ◽  
pp. 25176-25183
Author(s):  
M A Kumar ◽  
D E Timm ◽  
K E Neet ◽  
W G Owen ◽  
W J Peumans ◽  
...  

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