Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.7 (DNA polymerase)
17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An attempt was made to isolate and purify the important biological mediators that cause an increase in proliferative activity of fibroblasts following tissue injury. DNA synthesis and cellular growth, using cultured WI-38 fibroblasts, and DNA synthesis in an in vitro assay, using purified DNA polymerase, were stimulated by factors extracted from the lysosomal-mitochondrial fraction of normal guinea pig liver. These factors precipitated in 45 percent to 60 percent ethanol. They were insensitive to treatment with RNase, DNase and heating to 56 C for 30 minutes, but were inactivated at 100 C. isoelectric focusing of the active ethanol-precipitate resolved activity into five discrete fractions, one of which has been purified, using ion-exchange chromatography. The presence of these factors in normal tissue may explain the increase in proliferative activity of fibroblasts and other cells in the early stages of wound healing, via release caused by injury.
...
PMID:Isolation and purification of mediators of cell proliferation. 116 87

The possible existence of several species of DNA-dependent DNA polymerases in mammalian cells in addition to those 2 polymerases which are the smaller enzyme from nucleus and larger one from cytoplasm each having distinct characteristics, have been reported recently. In order to examine the heterogeneity of DNA polymerases in murine leukemia L1210 cells and to characterize their general properties, we have attempted to separate the DNA polymerase activities from L1210 cells. By diethylaminoethyl (DEAE)-cellulose chromatography (0.2 M-1M KCl) of the whole cell extract from L1210 solubilized by 1% Triton X-100 and 0.5 mM ethylenediaminetetraacetate (EDTA), 4 fractions with DNA-dependent DNA polymerase activities were obtained and designated as DD-1, DD-2, DD-3, and DD-4 for eluents with each corresponding concentration of 0.2, 0.3, 0.5, and 0.7 M KCl, respectively. They were distinguishable in properties such as template preference, divalent cation requirement, DNase sensitivity, isoelectric point (pI) and the behavior on the phosphocellulose chromatography. DD-1 preferred native DNA as template exhibiting similar characteristic as nuclear polymerase with low molecular weight and insensitivity to SH-inhibitors. DD-2, DD-3, and DD-4 utilized activated DNA most efficiently, while activity of DD-3 increased even in the presence of DNase 1 under the condition where the others were completely inhibited. Distribution of DNA polymerase activities in the cells is discussed briefly.
...
PMID:Separation and properties of DNA polymerase from murine leukemia L1210 cells. 117 38

The core of the Dane particle was shown to contain a DNA polymerase and a circular double stranded DNA with a molecular weight of 1.6 X 10(6) daltons which served as the primer-template for the enzyme. The product of the DNA polymerase reaction was in a base paired form and was covalently attached to the circular DNA. Neither the circular DNA nor the attached DNA product of the enzyme reaction was attacked by the DNase or released from intact cores until the cores were disrupted with sodium dodecyl sulfate, suggesting that they are internal components of the core. The DNA polymerase is a specific marker for Dane particles and can be used to distinguish sera with high and low concentrations of Dane particles. The DNA polymerase reaction can also be used to radiolabel Dane particle cores for a specific and sensitive radioimmunoprecipitation assay for antibody against the hepatitis B core antigen (anti-HBc).
...
PMID:DNA and DNA polymerase in the core of the Dane particle of hepatitis B. 118 30

Nuclear extracts, prepared from Autographa californica nuclear polyhedrosis virus-infected Spodoptera frugiperda cells during a time course of infection, were analyzed for activation of early gene transcription and for late gene transcription. The templates used in the in vitro transcription assays contained promoters for baculovirus genes that have been classified as immediate early, delayed early, and late. The promoters were derived from the baculovirus 39K, p26, gp64, and DNA polymerase genes. In addition, the adenovirus major late promoter was included in these studies. We found that transcription from promoters classified as immediate early or delayed early was accurately initiated by using extracts from uninfected cells. Furthermore, transcription from all early promoters tested was found to be transactivated by nuclear extracts prepared at 4 and 8 h postinfection. However, baculovirus enhancer-dependent transcriptional activation was not observed in tests with templates containing the hr5 enhancer sequence. Transcription from baculovirus late promoters was also not observed. A decline in transcription by nuclear extracts prepared from cells late in infection was associated with the presence of DNase activity.
...
PMID:In vitro transactivation of baculovirus early genes by nuclear extracts from Autographa californica nuclear polyhedrosis virus-infected Spodoptera frugiperda cells. 131 63

DNA polymerase I (pol I) from Escherichia coli has three well-defined activities: DNA polymerase, 3'-5' exonuclease, and 5'-3' exonuclease. We have raised monoclonal antibodies to pol I which selectively neutralize each of these three activities, thus supporting the model of separate active sites for each activity, heretofore exclusively demonstrated with proteolytic fragments of pol I. Antibodies from each class could bind pol I in the presence of antibodies of another class, indicating the existence of significant spatial separation between each of the three sites. In addition, several of the neutralizing antibodies were able to distinguish particular activities of the 5'-3' exonuclease. One of them, for example, inhibited the RNase H activity but not the DNase activity. Two other antibodies could, in addition to inhibiting the polymerase and the 3'-5' exonuclease, either stimulate or inhibit the 5'-3' exonuclease depending upon the assay conditions, particularly the ionic strength.
...
PMID:Selective immunoneutralization of the multiple activities of Escherichia coli DNA polymerase I supports the model for separate active sites and indicates a complex 5' to 3' exonuclease. 132 12

After high dose methotrexate (CAS 59-05-2) therapy of children with non-metastatic osteosarcoma the neutral DNase activity is missing in lymphocytes and in phytohemagglutinin (PHA)-stimulated lymphocytes. The neutral DNase activity reappeared in lymphocytes 14 days and in PHA-stimulated lymphocytes 10 days after the end of therapy. The DNA polymerase activity is low when neutral DNase is missing and increases when neutral DNase activity reappeared. The neutral DNase activity in lymphocytes and in PHA-stimulated lymphocytes is probably identical with DNase I. Drug induced changes in DNA conformation can enhance DNase I cleavage rate. It is assumed, that high dose methotrexate alters DNA conformation and therefore binds DNase I; after this, free DNase I is no more detectable.
...
PMID:Missing neutral DNase activity in lymphocytes and phytohemagglutinin-stimulated lymphocytes after high dose methotrexate therapy. 141 65

TuMV particles were purified from artificially infected leaves of Brassica juneaen, and TuMV-RNA was extracted from these particles. The virus thus purified showed typical nucleoprotein absorbent peak under UV light scanning, and the ratio of A260/A280 was 1.21. The RNA thus prepared showed typical ribonucleic acid absorbent peak, and the ratio of A260/A280 was 2.2. The RNA was then used as template of oligo (dT) 12-18 together with the end product of DNase digested calf thymus DNA were used as primer for the synthesis of cDNA. The length of double stranded cDNAs synthesized were distributed continuously with the sizes between 500-4300 bp. The ds-cDNA repaired by Klenow fragment was inserted into the Small site of pUC19 by blunt-end ligation. Then the recombinant molecules were used to transform E. coli strain DH5 alpha. Rapid electrophoresis of plasmid prepared by alkali method, EcoRI-HindIII digestion and in situ hybridization with 32P labeled TuMV-RNA showed that inserted fragments were with various sizes and complement to TuMV-RNA.
...
PMID:[Synthesis and molecular cloning of the cDNA of TuMV-RNA]. 176 57

Treatment of L929 cells with TNF alpha initiates apoptosis and subsequent cell death. The authors have visualized sites of DNA damage in situ by using DNA polymerase to synthesize new strands from the DNA strands breaks as starting point. Biotin-dUTP was incorporated into the newly synthesized strand and visualized by immunocytochemistry. DNA strand breaks were first observed 3 to 4 hours after contact with TNF alpha and preceded cell death. Limiting doses of TNF alpha caused DNA strand breaks only in a subpopulation of L929 cells. At a low dose, TNF alpha led to DNA damage without any subsequent loss of cell viability. The new assay also detects DNase-induced single strand breaks and thus is able to visualize apoptotic as well as non-apoptotic types of DNA damage.
...
PMID:Analysis of TNF alpha-induced DNA strand breaks at the single cell level. 186 16

A high molecular weight mitochondrial DNA (mtDNA) replication complex, associated with the mitochondrial membrane, was isolated by sucrose gradient centrifugation from purified wheat embryo mitochondria. This complex comprised the mtDNA as well as enzyme activities involved in the replication and transcription of the organelle genome, such as DNA polymerase, RNA polymerase and topoisomerase type I. The isolated complex is active in mtDNA and mtRNA synthesis in vitro. Electron microscopy and lipid analysis confirmed the membrane origin of this complex. Enzyme activities are resistant to physiological ionic strengths, 0.1-0.2 M KC1, while the membrane-mtDNA association is resistant up to 1 M KC1. DNase treatment of the complex released the DNA polymerase activity while protease treatment solubilized mtDNA, suggesting the direct interaction of mtDNA with membrane protein(s). The use of a novel approach to detect mtDNA fragments specifically retained by the mitochondrial membranes after Sal I digestion of the complex suggests that specific mtDNA sequences anchor mtDNA to mitochondrial membranes.
...
PMID:Isolation from wheat mitochondria of a membrane-associated high molecular weight complex involved in DNA synthesis. 189 1

A protein that stimulates DNA polymerase alpha/primase many-fold on unprimed poly(dT) was purified to homogeneity from extracts of cultured mouse cells. The protein contains polypeptides of approximately 132 and 44 kDa, and the total molecular mass of 150 kDa calculated from Stokes radius (54 A) and sedimentation coefficient (6.7 S) indicates that it contains one each of the two subunits. The purified "alpha accessory factor" (AAF) also stimulates DNA polymerase alpha/primase in the self-primed reaction with unprimed single-stranded DNA. In addition to these effects on the coordinate activities of DNA polymerase alpha and DNA primase, stimulatory effects were also demonstrated separately on both the polymerase and primase activities of the enzyme complex. However, there was no stimulation with DNase-treated ("activated") DNA under normal conditions for assay of DNA polymerase alpha. The stimulatory activity of mouse AAF is highly specific for DNA polymerase alpha/primase; no effect was observed with mouse DNA polymerases beta, gamma, or delta, nor with retroviral, bacteriophage, or bacterial DNA polymerases. Mouse AAF stimulated human DNA polymerase alpha/primase with several different templates, similar to results with the mouse enzyme. However, it had very little effect on the DNA polymerase/primase from either Drosophila embryo or from yeast.
...
PMID:Purification and properties of an accessory protein for DNA polymerase alpha/primase. 216 97


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---