Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.21.1 (DNase)
 7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using eukaryotic cells that have been rendered permeable to exogenously supplied nucleotides, we have characterized the activity of the poly(adenosine diphosphoribose) (poly(ADPR)) synthesis system and compared it to the DNA synthesis complex. The synthesis of poly(ADPR) is dependent on the presence of NAD and Mg2+. It does not require ATP, NaF or a monovalent cation. It is inhibited by N-ethylmaleimide. The reaction product conforms to the nuclease susceptibilities expected for poly(ADP ribose) in that it is degraded by venom phosphodiesterase but not by DNAase of RNAase. A comparison of the effects of inhibitors of poly(ADPR) synthesis and DNA synthesis clearly distinguishes between the two enzymatic systems. Nicotinamide, 5-methyl nicotinamide, thymidine, 5-bromo deoxyuridine, adenosine diphosphoribose, caffeine and formycin all inhibit poly(ADPR) synthesis but not DNA synthesis. In contrast, araCTP, cytembena and phosphonoacetic acid all inhibit DNA synthesis but not poly(ADPR) synthesis. Addition of DNAase to the permeable cells causes a marked stimulation of poly(ADPR) synthesis. L cells in logarithmic growth were found to have high levels of activity of the DNA synthesis complex and low levels of activity of the poly(ADPR) synthesis system. In contrast, cells at plateau phase density demonstrate a decrease in the activity of the DNA synthesis complex and a marked increase in activity of the poly(ADPR) synthesis system. When examined in the presence of added DNAase, the activity of the poly(ADPR) synthesis system is the same in cells obtained from log or plateau phase cultures. This indicates that the physiologic activity of the enzyme varies while the total amount of enzyme remains constant. When the permeable cells are allowed to synthesize both poly(ADPR) and DNA simultaneously, the synthesis of one polymer has no effect on the rate of synthesis of the other.
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PMID:Characterization and comparison of poly(adenosine dephosphoribose) synthesis and DNA synthesis in nucleotide-permeable cells. 20 14

Synthesis of the major DNA-binding protein (ICP8) was investigated in primary rabbit kidney (RK) and Vero cells infected with the syncytial (syn) strain HSZP or with the non-syn strain KOS of herpes simplex virus type 1 (HSV-1). Results showed the following: 1. In contrast to strain KOS, the rate of viral polypeptide synthesis was accelerated in Vero cells infected with strain HSZP. The ICP8 could be detected in the nuclei of cells by one hour post-infection (hr p. i.) where it became associated with the viral DNA (DNase sensitive form). Later on (7 hr p.i.), the synthesis of viral polypeptides decreased and no further translocation of ICP8 from the cytoplasm into the nucleus was observed. 2. Strain HSZP was approx. three times more resistant to the action of phosphonoacetic acid (PAA) than strain KOS. In order to block the synthesis of HSZP gamma-2 polypeptides, a concentration of 600 micrograms PAA/ml had to be used. Under this condition, the HSZP ICP8 was translocated into the cell nucleus at later interval only (7 hr p.i.), and it was still possible to release this polypeptide from the nucleus by DNase treatment. The failure of the HSZP ICP8 to associate with the nuclear matrix (DNase resistant form) of infected cells in the absence of viral DNA replication may reflect its predominant affinity for the viral DNA which, in turn, may be responsible for the observed accelerated synthesis of the HSZP polypeptides in infected Vero cells. 3. In primary RK cells infected with strain HSZP the ICP8 did not translocate into the cell nucleus. Therefore, no gamma-2 polypeptides were synthesized.
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PMID:The synthesis of the major DNA-binding protein (ICP8) in cells infected with the strain HSZP or KOS of herpes simplex virus type 1. 168 15

A cell-free system that catalyzes DNA replication was prepared from cytoplasmic extracts of Vero cells infected with African swine fever virus (ASFV). The cells were permeabilized with lysolecithin and disrupted by mild mechanical action and the nuclei were removed by low-speed centrifugation. Extracts prepared from infected cells at the time of maximal DNA replication incorporated [alpha-32P]dTTP into acid-insoluble material that was sensitive to DNase and resistant to RNase. The reaction was inhibited by phosphonoacetic acid, an inhibitor of ASFV-specific DNA polymerase. Extracts from mock-infected cells had a negligible activity. Micrococcal nuclease-treated extracts were able to replicate added virion DNA or viral replicative DNA. An increase in the mass of DNA detected by ethidium bromide staining and by dot blot hybridization with ASFV DNA showed that the incorporation was due to true replication. Plasmid DNA was also replicated, which indicates that ASFV-specific DNA polymerase does not require a virus-specific origin of replication. The pattern of fragments generated by EcoRI digestion of the in vitro product was characteristic of viral replicative DNA. Hybridization with a recombinant plasmid containing a terminal fragment of ASFV DNA confirmed the presence of dimer terminal ASFV fragments presumably generated from concatemeric replicative intermediates.
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PMID:In vitro DNA replication by cytoplasmic extracts from cells infected with African swine fever virus. 221 42

Rta, the gene product of Kaposi's sarcoma-associated herpesvirus (KSHV) encoded mainly in open reading frame 50 (ORF50), is capable of activating expression of viral lytic cycle genes. What was not demonstrated in previous studies was whether KSHV Rta was competent to initiate the entire viral lytic life cycle including lytic viral DNA replication, late-gene expression with appropriate kinetics, and virus release. In HH-B2, a newly established primary effusion lymphoma (PEL) cell line, KSHV ORF50 behaved as an immediate-early gene and autostimulated its own expression. Expression of late genes, ORF65, and K8.1 induced by KSHV Rta was eliminated by phosphonoacetic acid, an inhibitor of viral DNA polymerase. Transfection of KSHV Rta increased the production of encapsidated DNase-resistant viral DNA from HH-B2 cells. Thus, introduction of an ORF50 expression plasmid is sufficient to drive the lytic cycle to completion in cultured PEL cells.
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PMID:Kaposi's sarcoma-associated herpesvirus open reading frame 50/Rta protein activates the entire viral lytic cycle in the HH-B2 primary effusion lymphoma cell line. 1084 8