scholarly journals Deoxyribonucleic acid synthesis in mammalian nuclei. Incorporation of deoxyribonucleotides and chain-terminating nucleotide analogues

1971 ◽  
Vol 121 (5) ◽  
pp. 803-809 ◽  
Author(s):  
M. A. Waqar ◽  
L. A. Burgoyne ◽  
M. R. Atkinson
Keyword(s):  
Dna Synthesis ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Deoxyribonucleic Acid Synthesis ◽  
Dna Chain ◽  
Relationship Of ◽  
The Relationship ◽  
Neighbour Analysis

The properties of a nuclear preparation from rat liver and thymus are described. (1) Nearest-neighbour analysis after incorporation of 32P-labelled nucleotide residues from dATP, dCTP, dGTP, dTTP and arabinofuranosyl analogues of CTP and ATP shows template-dependent DNA synthesis. (2) Where primer termini are limiting, incorporation of arabinofuranosyl analogues of AMP and CMP residues proceeds to a limit indicating that both of these analogues are DNA chain terminators. (3) No large differences have been found between the priming potentialities or the intrinsic DNA polymerase activities of nuclei from resting or regenerating liver and the relationship of this DNA synthesis in vitro to DNA replication or repair in vivo is briefly discussed.

scholarly journals Effect of drugs on deoxyribonucleic acid synthesis in isolated mammalian cell nuclei. Comparison with partially purified deoxyribonucleic acid polymerases

1979 ◽  
Vol 178 (3) ◽  
pp. 621-626 ◽  
Author(s):  
J F Burke ◽  
P M Duff ◽  
C K Pearson
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Cell Nuclei ◽  
Isolated Nuclei ◽  
Dna Polymerase Alpha ◽  
Polymerase Beta ◽  
Deoxyribonucleic Acid Synthesis

In order to ascertain the identity of the DNA-dependent DNA polymerase responsible for the observed DNA synthesis in nuclei isolated from baby-hamster kidney (BHK-21/C13) cells a comparative study was carried out on the effects of some drugs, reported to influence DNA synthesis, on DNA synthesis catalysed by these nuclei and by partially purified DNA polymerase-alpha and -beta. In all cases DNA synthesis by isolated nuclei and polymerase-alpha was inhibited to similar extents by N-ethylmaleimide, p-hydroxymercuribenzoate, novobiocin, heparin and phosphonoacetic acid; polymerase-beta was much less affected by these compounds. Ethidium bromide inhibited all DNA synthesis to similar extents, although at low concentrations (about 2 microgram/ml) synthesis in isolated nuclei was stimulated. The results are discussed in relation to the proposal that DNA polymerase-alpha catalyses the covalent extension of Okazaki fragments that these nuclei carry out in vitro.

USE OF I125-LABELED 5-IODO-2′-DEOXYURIDINE FOR THE MEASUREMENT OF DNA SYNTHESIS IN MAMMALIAN CELLS IN VITRO

1963 ◽  
Vol 41 (11) ◽  
pp. 2343-2351 ◽  
Author(s):  
S. Mak ◽  
J. E. Till
Keyword(s):  
Dna Synthesis ◽  
Mammalian Cells ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
X Rays ◽  
Beta Particles ◽  
Deoxyribonucleic Acid Synthesis ◽  
Gamma Emitter

The use of isotopically labeled 5-iodo-2′-deoxyuridine (I125UdR) for determination of the rate of deoxyribonucleic acid synthesis in mammalian cells in vitro has been investigated. The results obtained indicate that for this purpose I125UdR is a suitable substitute for the more commonly used DNA precursor, tritium-labeled thymidine (H3TdR). I125UdR appears to be incorporated specifically into the DNA of cells in culture, and has been demonstrated to compete with H3TdR, although the Km for H3TdR was smaller than that of I125UdR by a factor of approximately 4. The amount of label incorporated into DNA of cells increased linearly with time. When the rate of DNA synthesis was reduced by exposure of the cells to various doses of X-rays, the ratio of I125UdR incorporation to H3TdR incorporation into DNA of cells was found to be a constant, which supports the view that uptake of the analogue provides as reliable an indication of effects upon the rate of DNA synthesis as does that of H3TdR. The chief advantage of I125UdR over H3TdR is that I125 is a gamma emitter, so that the difficulties encountered in detection of the low energy beta particles from H3 may be avoided.

Modulation of mitogenic responsiveness by staphylococcal peptidoglycan

1980 ◽  
Vol 30 (2) ◽  
pp. 431-438
Author(s):  
R Dziarski
Keyword(s):  
Concanavalin A ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Pokeweed Mitogen ◽  
Mouse Splenocytes ◽  
Deoxyribonucleic Acid Synthesis ◽  
Cell Mitogen ◽  
Kinetics Of

Staphylococcal peptidoglycan can modulate in vivo and in vitro antibody responses and is a B-cell mitogen. The effect of in vivo peptidoglycan treatment on the subsequent in vitro mitogenic responsiveness of mouse splenocytes to phytohemagglutinin, concanavalin A, pokeweed mitogen, and lipopolysaccharide was studied by measuring changes in deoxyribonucleic acid synthesis. Injection of peptidoglycan caused a 100% increase in responsiveness to phytohemagglutinin and pokeweed mitogen and a 45% increase in responsiveness to concanavalin A. Responsiveness to lipopolysaccharide was decreased by 40%. Increased phytohemagglutinin and decreased lipopolysaccharide responses were not due to changes in the kinetics of the response or optimal concentrations of these mitogens. Increased responsiveness to phytohemagglutinin lasted for 2 weeks after peptidoglycan injection. Neither increased background deoxyribonucleic acid synthesis nor changes in the proportion of T cells after peptidoglycan treatment fully accounted for the changes in responsiveness to the mitogens. In vitro costimulation with peptidoglycan and phytohemagglutinin, lipopolysaccharide, concanavalin A, or pokeweed mitogen resulted in interference of the response. Cell separation experiments indicated that peptidoglycan-induced modulation of mitogenic responsiveness was mediated by B lymphocytes.

scholarly journals TRANSIENT PHOSPHORYLATION OF DEOXYRIBOSIDES AND REGULATION OF DEOXYRIBONUCLEIC ACID SYNTHESIS

1961 ◽  
Vol 11 (2) ◽  
pp. 311-319 ◽  
Author(s):  
Yasuo Hotta ◽  
Herbert Stern
Keyword(s):  
Dna Synthesis ◽  
Enzyme Induction ◽  
Deoxyribonucleic Acid ◽  
Lilium Longiflorum ◽  
Acid Synthesis ◽  
Deoxyribonucleic Acid Synthesis ◽  
Patterns Of Behavior

Microspores isolated from Lilium longiflorum and Trillium erectum were studied with respect to their capacities for phosphorylating deoxyribosides in vitro. It was found that such capacities are manifest only during brief intervals of time adjacent to periods of DNA synthesis, and that none of the neighboring cells in the anther acquire them. The observed patterns of behavior are interpreted in terms of enzyme induction as a device for regulating DNA synthesis.

USE OF I125-LABELED 5-IODO-2′-DEOXYURIDINE FOR THE MEASUREMENT OF DNA SYNTHESIS IN MAMMALIAN CELLS IN VITRO

1963 ◽  
Vol 41 (1) ◽  
pp. 2343-2351 ◽  
Author(s):  
S. Mak ◽  
J. E. Till
Keyword(s):  
Dna Synthesis ◽  
Mammalian Cells ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
X Rays ◽  
Beta Particles ◽  
Deoxyribonucleic Acid Synthesis ◽  
Gamma Emitter

The use of isotopically labeled 5-iodo-2′-deoxyuridine (I125UdR) for determination of the rate of deoxyribonucleic acid synthesis in mammalian cells in vitro has been investigated. The results obtained indicate that for this purpose I125UdR is a suitable substitute for the more commonly used DNA precursor, tritium-labeled thymidine (H3TdR). I125UdR appears to be incorporated specifically into the DNA of cells in culture, and has been demonstrated to compete with H3TdR, although the Km for H3TdR was smaller than that of I125UdR by a factor of approximately 4. The amount of label incorporated into DNA of cells increased linearly with time. When the rate of DNA synthesis was reduced by exposure of the cells to various doses of X-rays, the ratio of I125UdR incorporation to H3TdR incorporation into DNA of cells was found to be a constant, which supports the view that uptake of the analogue provides as reliable an indication of effects upon the rate of DNA synthesis as does that of H3TdR. The chief advantage of I125UdR over H3TdR is that I125 is a gamma emitter, so that the difficulties encountered in detection of the low energy beta particles from H3 may be avoided.

Adrenocortical function in aging exercise-trained rats

1977 ◽  
Vol 43 (5) ◽  
pp. 839-843 ◽  
Author(s):  
J. A. Severson ◽  
R. D. Fell ◽  
J. G. Tuig ◽  
D. R. Griffith
Keyword(s):  
Age Groups ◽  
Plasma Corticosterone ◽  
Treadmill Running ◽  
Adrenocortical Function ◽  
Elevated Plasma ◽  
Corticosterone Concentration ◽  
Relationship Of ◽  
The Relationship

Plasma corticosterone concentrations and in vitro adrenal secretion of corticosterone were determined in exercise-trained rats. Rats, 100, 200, and 300 days of age, were trained for a 10-wk period by treadmill running. Following the training program, rats were subjected to an acute bout of swimming. Acute swimming elevated plasma corticosterone concentrations in all age groups. At 170 days of age, the plasma corticosterone concentration following swimming was higher in exercise-trained rats than in controls. The opposite was true of acutely swum rats at 270 and 370 days of age. Acute swimming elevated the in vitro adrenal gland response to adrenocorticotropic hormone stimulation in control rats at all ages and in trained rats at 170 days of age. The in vivo relationship of epinephrine and the pituitary adrenal system is suggested as a mechanism which could have caused this response. The relationship of secretion rates to plasma corticosterone concentrations indicated that extra-adrenal mechanisms, such as decreased turnover, were also responsible for the elevated plasma corticosterone levels observed in response to acute swimming.

scholarly journals Ornithine decarboxylase activity and the onset of deoxyribonucleic acid synthesis in regenerating liver

1978 ◽  
Vol 170 (1) ◽  
pp. 123-127 ◽  
Author(s):  
J A McGowan ◽  
N Fausto
Keyword(s):  
Dna Synthesis ◽  
Ornithine Decarboxylase ◽  
Time Course ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Decarboxylase Activity ◽  
Ornithine Decarboxylase Activity ◽  
Low Protein ◽  
Deoxyribonucleic Acid Synthesis ◽  
Second Peak

Compared with normally fed animals, rats fed on a low-protein diet for 3 days exhibit a considerable delay in DNA synthesis after partial hepatectomy. In the regenerating livers of these animals (a) the timing of the first peak of ornithine decarboxylase activity is not altered and (b) the second peak of enzyme activity is delayed by a few hours, but polyamine concentrations are similar to those of normally fed rats. The results suggest that regardless of the possible effect of polyamines on DNA synthesis, the time course of ornithine decarboxylase activity appears to be independent of the onset of DNA replication in regenerating livers.

scholarly journals Effect of incorporation of cidofovir into DNA by human cytomegalovirus DNA polymerase on DNA elongation.

1997 ◽  
Vol 41 (3) ◽  
pp. 594-599 ◽  
Author(s):  
X Xiong ◽  
J L Smith ◽  
M S Chen
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Human Cytomegalovirus ◽  
Chain Elongation ◽  
Exonuclease Activity ◽  
Dna Chain ◽  
Alternate Substrate

Cidofovir (CDV) (HPMPC) has potent in vitro and in vivo activity against human cytomegalovirus (HCMV), CDV diphosphate (CDVpp), the putative antiviral metabolite of CDV, is an inhibitor and an alternate substrate of HCMV DNA polymerase. CDV is incorporated with the correct complementation to dGMP in the template, and the incorporated CDV at the primer end is not excised by the 3'-to-5' exonuclease activity of HCMV DNA polymerase. The incorporation of a CDV molecule causes a decrease in the rate of DNA elongation for the addition of the second natural nucleotide from the singly incorporated CDV molecule. The reduction in the rate of DNA (36-mer) synthesis from an 18-mer by one incorporated CDV is 31% that of the control. However, the fidelity of HCMV DNA polymerase is maintained for the addition of the nucleotides following a single incorporated CDV molecule. The rate of DNA synthesis by HCMV DNA polymerase is drastically decreased after the incorporation of two consecutive CDV molecules; the incorporation of a third consecutive CDV molecule is not detectable. Incorporation of two CDV molecules separated by either one or two deoxynucleoside monophosphates (dAMP, dGMP, or dTMP) also drastically decreases the rate of DNA chain elongation by HCMV DNA polymerase. The rate of DNA synthesis decreases by 90% when a template which contains one internally incorporated CDV molecule is used. The inhibition by CDVpp of DNA synthesis by HCMV DNA polymerase and the inability of HCMV DNA polymerase to excise incorporated CDV from DNA may account for the potent and long-lasting anti-CMV activity of CDV.

Nonrandom substitution of 2-aminopurine for adenine during deoxyribonucleic acid synthesis in vitro

Biochemistry ◽  
1981 ◽  
Vol 20 (21) ◽  
pp. 6235-6244 ◽  
Author(s):  
Reynaldo C. Pless ◽  
Lore M. Levitt ◽  
Maurice J. Bessman
Keyword(s):  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Deoxyribonucleic Acid Synthesis
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