scholarly journals Differential expression of crown gall tumor markers in transformants obtained after in vitro Agrobacterium tumefaciens-induced transformation of cell wall regenerating protoplasts derived from Nicotiana tabacum

1981 ◽  
Vol 78 (7) ◽  
pp. 4344-4348 ◽  
Author(s):  
G. J. Wullems ◽  
L. Molendijk ◽  
G. Ooms ◽  
R. A. Schilperoort
Planta ◽  
1982 ◽  
Vol 156 (4) ◽  
pp. 364-368 ◽  
Author(s):  
A. -M. Bouckaert-Urban ◽  
G. Brouwers ◽  
L. Thoelen ◽  
J. C. Vendrig

PROTOPLASMA ◽  
1959 ◽  
Vol 52 (1) ◽  
pp. 143-144
Author(s):  
W. A. Kurt Schmidt
Keyword(s):  

Nature ◽  
1979 ◽  
Vol 277 (5692) ◽  
pp. 129-131 ◽  
Author(s):  
L. MÁRTON ◽  
G. J. WULLEMS ◽  
L. MOLENDIJK ◽  
R. A. SCHILPEROORT

1963 ◽  
Vol 41 (7) ◽  
pp. 1503-1518 ◽  
Author(s):  
R. M. Hochster ◽  
V. M. Chang

The enzyme RNA polymerase has been partially purified from cell-free extracts of the crown-gall tumor-inducing organism Agrobacterium tumefaciens. The four triphosphates ATP, CTP, GTP, and UTP, manganese (or magnesium) ions, and DNA are all required for activity. DNA acts as a template in the formation of the new RNA molecule the base composition of which exactly mimics that of the particular DNA used. The dependence of the reaction on time, pH, and on the concentrations of nucleoside triphosphate, DNA, and protein has been worked out. The exact requirements of the entire system are delineated, the effect of physical alteration of the DNA used (heating, cooling, sonic oscillation) has been examined and a new observation made on the stimulation of DNA action by 1-minute sonic pretreatment.Actinomycin D is shown to inhibit the reaction completely at 2.8 × 10−5 M while atabrine, a new inhibitor, requires a concentration of 3.3 × 10−3 M under the conditions specified. Hydrolysis of the reaction product by means of a variety of procedures and other information obtained show that the reaction product is, indeed, RNA.The data reported herein are regarded as providing a satisfactory explanation for the mechanism of biosynthesis of at least one type of RNA (presumably "messenger" RNA) in A. tumefaciens.


1961 ◽  
Vol 39 (11) ◽  
pp. 1695-1704 ◽  
Author(s):  
A. Vardanis ◽  
R. M. Hochster

An investigation of the nucleotide specificity of the polynucleotide phosphorylase of Agrobacterium tumefaciens was undertaken, using the measurable increase in viscosity as an index of activity. It was found that ADP and CDP were polymerized readily and at approximately equal rates. The enzyme exhibited more moderate activity with UDP and was completely inactive with GDP. The ineffectiveness of the enzyme with mixtures of all four ribonucleoside diphosphates was traced to the ability of GDP to act as an inhibitor in the polymerization of the other diphosphates. Evidence is presented to show that the inhibition of poly A synthesis effected by GDP is competitive. On the basis of the results obtained it is concluded that the polynucleotide phosphorylase is not likely to be responsible for RNA synthesis in A. tumefaciens.


1961 ◽  
Vol 39 (4) ◽  
pp. 773-785 ◽  
Author(s):  
A. Vardanis ◽  
R. M. Hochster

Cell-free extracts of the crown-gall tumor inducing organism Agrobacterium tumefaciens (strain B6) have been shown to convert ATP to ADP relatively slowly. An adenylate kinase of only moderate activity has been found.Crude extracts of this organism contain an extremely active polynucleotide phosphorylase which rapidly catalyzes the synthesis of polyadenylate from ADP, releasing Piin stoichiometric proportions. Extracts are also shown to exhibit some phosphodiesterase activity towards the polyadenylate so formed.Even though the enzymatic conversions of adenosine and of IMP to hypoxanthine are shown to occur readily it has not been possible to demonstrate any metabolic link between AMP and either adenosine or IMP. Extracts of A. tumefaciens have the unusual property of being unable to metabolize further AMP or other similar mononucleotides (with the exception of IMP).It is shown also that polynucleotide phosphorylase is active not only in extracts of crown-gall tumor inducing organisms but also in those of at least one related non-tumorogenic species of Agrobacterium.


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