Specificity of the stimulation of in vitro ribonucleic acid synthesis by guanosine 5′-diphosphate 3′-diphosphate

1975 ◽  
Vol 141 (4) ◽  
pp. 277-284 ◽  
Author(s):  
David E. Smolin ◽  
H. E. Umbarger
1967 ◽  
Vol 105 (2) ◽  
pp. 779-782 ◽  
Author(s):  
F. Stirpe ◽  
L. Fiume

1. Injection of α-amanitin to mice causes a decreased incorporation of [6−14C]-orotic acid into liver RNA in vivo. 2. The activity of RNA polymerase activated by Mn2+ and ammonium sulphate is greatly impaired in liver nuclei isolated from mice poisoned with α-amanitin, and is inhibited by the addition of the same toxin in vitro. 3. The activity of the Mg2+-activated RNA polymerase is only slightly affected by α-amanitin either administered to mice or added in vitro.


1969 ◽  
Vol 36 (3) ◽  
pp. 469-478 ◽  
Author(s):  
R. W. Smith ◽  
R. F. Glascock

SummaryA study was made of the changes in the rates of oxidation of the C(1), C(2) and C(6) atoms of glucose and in the pathways of glucose catabolism in sheep udder tissue in vitro which occurred when acetate and pyruvate were added.Whereas in rat mammary tissue the rate of oxidation of the C(1) atom of glucose was very much greater than that of the C(6) atom, the ratio of the rates of oxidation of these 2 atoms in sheep tissue was less than 2 when glucose was the only substrate.The addition of acetate resulted in an unequal stimulation of the oxidation of these 2 atoms, with the result that the ratio of their rates of oxidation was about doubled. The rate of oxidation of the C(2) atom was also increased.Acetate also increased the participation of the pentose phosphate pathway in glucose catabolism as measured by the incorporation of the C(1) and C(6) atoms of glucose into fatty acids, lactic acid and glycerol.Pyruvate produced little effect on the rate of oxidation of the C(1) atom but somewhat depressed that of the C(6) atom of glucose. At the same time, it caused a large increase in the participation of the pentose phosphate pathway.These results are discussed with reference to re-cycling of glucose carbon in the pentose phosphate pathway and to the relationship between that pathway and fatty acid synthesis. It is noted that the incorporation of glucose carbon into the 3 intermediates used gave values for the participation of that pathway which were in better agreement than was obtained in rat tissue. It is concluded that triose phosphates are more nearly in equilibrium in sheep than in rat mammary tissue.


1970 ◽  
Vol 117 (5) ◽  
pp. 853-859 ◽  
Author(s):  
T. C. Hall ◽  
K. L. Tao

1. A procedure for measuring rates of aminoacyl-tRNA synthesis in vitro and in intact leaves is presented. 2. Leaf discs showed rates close to those of intact leaves. 3. Cell-free preparations showed similar rates when assayed by pyrophosphate exchange, but actual aminoacyl-tRNA formation rates appeared to be much lower. Evidence is presented that dilution of supplied labelled amino acids was a major factor causing the low apparent rates. 4. Attempts to strip endogenous amino acids from plant tRNA resulted in low acceptor capability of the tRNA.


1974 ◽  
Vol 140 (3) ◽  
pp. 565-567 ◽  
Author(s):  
P. Davies ◽  
K. Griffiths

Stimulation of prostatic RNA polymerase in vitro by prostatic 17β-hydroxy-5α-androstan-3-one (5α-dihydrotestosterone)–receptor complexes has been previously reported. By use of the selective inhibitor, α-amanitin, we have shown that both nucleolar and extranucleolar RNA polymerase activities may be stimulated, but stimulation is abolished at high ionic strength.


1991 ◽  
Vol 34 (7) ◽  
pp. 1969-1974 ◽  
Author(s):  
Joerg Metzger ◽  
Guenther Jung ◽  
Wolfgang G. Bessler ◽  
Petra Hoffmann ◽  
Marianne Strecker ◽  
...  

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