Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.21.3 (deoxyribonuclease)
 1,528 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of Rolly No. 11 strain herpes simplex virus infection of HeLa cells in culture on deoxynucleotide metabolism and the level of various enzymes concerned with the biosynthesis of DNA has been investigated. Of 18 enzyme activities studied, thymidine kinase, DNA polymerase and deoxyribonuclease were markedly augmented, a finding in agreement with previous reports. Deoxycytidine kinase, ribonucleotide reductase, thymidylate kinase and deoxycytidylate deaminase activities, in contrast with previous reports, did not increase; the activities of the other enzymes studied, also did not increase. Whereas most of the radioactivity derived from [14-C] thymidine in the acid-soluble fraction of the uninfected cells was present as deoxythymidine triphosphate, that present in the infected cells was primarily in the form of deoxythymidine monophosphate. Thus, in the infected cell deoxythymidylate kinase is a rate-limiting enzyme in the biosynthesis of deoxythymidine triphosphate. A marked increase in the pools of the four naturally occurring deoxynucleoside triphosphates (dTTP, dCTP, dATP, dGTP) was found. The rate of formation of the virus-induced enzymes was determined, as were the various nucleoside triphosphate pools and the other phosphorylated derivatives of thymidine; a maximum was reached for all these csmponents between 6 to 8 h post infection. Although an apparent greater synthesis of DNA occurred in the uninefected cells, when the specific activity of the radioactive deoxythymidine triphosphate was taken into account, there was actually a greater rate of DNA synthesis in the infected cells, with the peak at 8 h post infection.
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PMID:Deoxyribonucleotide metabolism in Herpes simplex virus infected HeLa cells. 16 49

Treatment of neuroblastoma cells with dibutyryl-adenosine 3':5'-monophosphate or adenine induced axon formation and a three-fold increase in the polyadenylate, poly(A), content of the polysomal mRNA. The extracted poly(A) contained 90% adenylic acid and showed a mobility of 6--7 S in dodecylsulfate-polyacrylamide gel electrophoresis. Treatment with dibutyryl-adenosine 3':5'-monophosphate or adenine, also induced a 4--6 fold increase in a nuclear enzymic activity that incorporated [3H]ATP to an acid-insoluble polymer in a cell-free system. This polymer, like poly(A) extracted from the polysomal mRNA, was bound at high salt concentration to nitrocellulose filters. [3H]ATP incorporation was Mg2+-dependent, sensitive to ribonuclease and EDTA and resistant to deoxyribonuclease and actinomycin D. There was no incorporation of [3H]UTP or [3H]dTTP and addition of TUP, CTP and GTP did not increase the incorporation of [3H]ATP. 5-Bromodeoxyuridine induced axon formation of neuroblastoma cells and poly(A) polymerase activity, without increasing the poly(A) content in the polysomal mRNA. The results indicate that induction of axon formation of neuroblastoma cells is associated with an increase in the activity of poly(A) polymerase. It is suggested that the induction of this enzyme may be generally involved in cell differentiation.
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PMID:Induction of polyadenylate polymerase and differentiation in neuroblastoma cells. 17 99

A new in vitro system for T4 DNA replication was developed by concentrating cell lysates on cellophane disks. The time course of [3H]dTTP incorporation into DNA by the system was separated into two phases: one was a very rapid incorporation which was terminated within 2 min (phase I reaction), and the other was a slow but continuous incorporation thereafter (phase II reaction). More than half of the phase I reaction product was Escherichia coli DNA, but the phase II reaction was mostly T4 DNA. Phase II reaction required four deoxyribonucleoside triphosphates, ATP, Mg2+, and KCl. 5-Hydroxymethyldeoxycytidine triphosphate was essential for the reaction and not substitutable by dCTP. The presence of KCN or NaN3 in the reaction mixture did not interfere with [3H]dTTP incorporation, but the addition of deoxyribonuclease completely degraded the system. Alkaline sucrose sedimentation analysis of phage II reaction product revealed that phase II reaction proceeded by the discontinuous mode of DNA replication as in vivo. After T4 infection, the activity for phase II reaction appeared in parallel with the activity of T4 phage DNA replication in vivo.
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PMID:Replication of bacteriophage T4 DNA in vitro. I. Basic properties of the system. 78 23

Four nuclear thermosensitive mutants have been obtained in which induction of up 100% cytoplasmic petite mutants (rho-) is observed upon cell incubation at 36 degrees C. For a given incubation time at 36 degrees C, the percentage of rho- is increased by preliminary gamma-ray irradiation. Under these conditions, the induction of rho- is a linear function of the irradiation dose. The retention of genetic information by rho- and of mitochondrial DNA synthesis in vivo and in vitro exclude that the mutants are deficient in the replication of mitochondrial DNA. The degradation of mitochondrial DNA labeled with [3H]dTTP in isolated mitochondria, has been monitored at 26 degrees C and at 36 degrees C after addition of 0.5% Triton X-100 in the presence or in the absence of ethidium bromide. In assays carried out at 26 degrees C, the degradation of mitochondrial DNA is similar in the parental strain and in the mutant gamma s rho 2. However, at 36 degrees C, the degradation of mitochondrial DNA is slower in the mutant. We have shown that a mitochondrial membrane deoxyribonuclease acting on double-stranded DNA at acid pH is thermosensitive in the mutant. Analysis of the meiotic segregants of a tetrad issued from the cross of the mutant with an isogenic parental strain shows co-segregation of rho- induction and of nuclease thermosensitivity in a 2:2 Mendelian pattern. These results suggest that a mitochondrial deoxyribonuclease is involved in the repair of damages caused to mitochondrial DNA by elevated temperature and by x-rays.
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PMID:Repair of mitochondrial DNA in Saccharomyces cerevisiae. Induction of cytoplasmic petite mutants in a nuclear mutant exhibiting thermosensitive mitochondrial deoxyribonuclease activity. 703 19

Two unusual enzymatic activities are required for the realization of a single molecule sequencing: a polymerase for copying a deoxyribonuclease (DNA) target into complementary flurophore-labeled DNA, and an exonuclease for the successive hydrolysis of the completely dye-labeled DNA. Recently, we found that the wild-type Klenow fragment of Escherichia coli DNA polymerase I is well-suited for the synthesis of DNA in a reaction set-up that contains exclusively specific rhodamine-labeled analogs of the natural pyrimidine nucleotides (dCTP and dTTP). This protocol describes the procedure used for the preparation of DNA that is labeled at all pyrimidine bases of one strand, as well as an example of enzymatic downstream processing of the DNA product.
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PMID:High-density labeling of DNA for single molecule sequencing. 1519 7