Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

A cell-free system for the study of transcription of African swine fever virus (ASFV) mRNA was developed from cytoplasmic extracts of infected cells permeabilized with lysolecithin. Extracts prepared from infected cells early and late after infection incorporated [alpha-32P]UTP into acid-insoluble material that was resistant to DNase and sensitive to RNase. The incorporation was inhibited by actinomycin D but not by alpha-amanitin. The presence of the nuclei was not required. In vitro transcription was optimal at pH 7.9 and at concentrations of 100 mM NH4Cl, 5 mM magnesium acetate, and 250 microM MnCl2. Early infected cell extracts transcribed from endogenous viral DNA a set of RNAs similar in electrophoretic migration to that observed in intact infected cells. Late infected cell extracts seemed to be unable to transcribe new RNA species besides those transcribed early after infection. The activity of the extracts could be made dependent on exogenous templates by digestion with micrococcal nuclease. RNAs transcribed after addition of native or denatured viral DNA to nuclease-treated extracts were indistinguishable from those transcribed from endogenous viral DNA. Late infected cell extracts digested with micrococcal nuclease were also active in transcribing virus-specific RNA from p2SB21, a recombinant plasmid containing the SalI B fragment of ASFV DNA.
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PMID:In vitro transcription by cytoplasmic extracts from cells infected with African swine fever virus. 259 35

The English isolate of rat cytomegalovirus (RCMV) encodes a 20-kDa protein with a C-type lectin-like domain that is expressed in the delayed-early and late phases of the viral replication cycle. Genomic sequence analysis of the restriction fragment KpnR of RCMV revealed significant homology to several C-type lectin-containing molecules implicated in natural killer (NK) and T-cell interactions, as well as genes from four poxviruses and African swine fever virus. The gene is spliced into five exons and shows a splicing pattern with exon boundaries similar to those observed in the human differentiation antigen CD69. The cap site of the gene was mapped by RNase protection, 5' rapid amplification of cDNA ends, and primer extension experiments. This analysis demonstrated that the core promoter of the RCMV lectin-like gene contains a GATA rather than a TATA box. Splicing patterns were confirmed with isolates from an infected-cell cDNA library. A unique aspect of the protein is that its translation is not initiated by the canonical methionine but rather by alanine. To study its role in virus replication and pathogenesis, a recombinant virus was constructed in which the gene is interrupted. Replication in tissue culture was similar to that of wild-type virus.
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PMID:Identification and characterization of a spliced C-type lectin-like gene encoded by rat cytomegalovirus. 1113 73

Ribonucleases (RNases) have therapeutic potential against cancer and viral diseases and have been reported to inhibit replication of the human immunodeficiency virus type 1 (HIV-1) in chronically infected cell lines. The ribonuclease eosinophil-derived neurotoxin (EDN) is responsible for the anti-HIV-1 activity of a soluble factor produced in response to human alloantigens (ASF). Four recombinant RNases (EDN; a four amino acid extension of the N-terminus EDN, -4EDN; RNase A; and angiogenin) were tested for inhibition of HIV-1 replication in PHA blasts. All RNases showed anti-HIV-1 activity, irrespective of whether the RNases were added before, during, or 2 h after infection. Polyclonal antibodies against the four RNases blocked the antiviral activity. ASF inhibited HIV-1 replication in vitro if added up to 4 h after infection. We demonstrated that allostimulation induced EDN, RNase A, and angiogenin mRNA expression in peripheral blood mononuclear cells (PBMCs), although only EDN protein was detected. We identified monocytes and dendritic cells, but not macrophages or T cells, as EDN-producing cells. These findings raise the possibilities that multiple naturally occurring RNases may contribute to protection against HIV-1 infection and could be considered for utilization in HIV-1 therapy.
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PMID:Ribonucleases in HIV type 1 inhibition: effect of recombinant RNases on infection of primary T cells and immune activation-induced RNase gene and protein expression. 1698 16