Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:BIOD00001 (DNase I)
 8,324 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At various times following estrogen administration, the nuclear matrix was isolated from the liver of male Xenopus laevis by sucrose gradient centrifugation of nuclei treated with a high-salt buffer and DNase I in the presence of a proteolytic inhibitor (PMSC--phenylmethyl sulfonyl chloride). Electron micrographs of the nuclear matrix demonstrate a sponge-like network attached to a well-defined inner envelope with a ribosome-free outer envelope. Chemical analyses show that the HSB-DNase-treated nuclei consist of 16% DNA, 2% RNA, and 82% protein, a composition that is consistent with that of nuclear matrices isolated from other species. The specific activity of the matrix-associated RNA following estrogen treatment appears to be maximally enhanced after 5 h and decreases until approximately 12 h, when the activity begins to increase again.
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PMID:Isolation and characterization of the nuclear matrix from the male Xenopus laevis following estrogen administration: kinetics of [3H] uridine incorporation. 9 25

Deoxyribonuclease I has been purified from bovine parotid gland. The purification procedure utilizes an acid extraction of minced parotid gland, salt fractionation, gel filtration, and ion-exchange chromatography. The last step, chromatography on Sulfopropyl-Sephadex, resolves the enzymatic activity into several fractions. The major fraction, designated DNase A, was subjected to further investigation. This enzyme has, as expected, an alkaline pH optimum and an obligate requirement for divalent cations. The presence of calcium chloride protects DNase A from inactivation by proteolytic enzymes. Despite the previously described immunologic dissimilarity, there appears to be a large amount of homology between the parotid and pancreatic DNase's.
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PMID:Purification and partial characterization of deoxyribonuclease I from bovine parotid gland. 26 62

Nuclei and chromatin from trout testis cells were digested with three different nucleases (DNase I, DNase II, and micrococcal nuclease), and the acid-soluble proteins that were solubilized and those remaining bound to the nuclease-resistant DNA were compared electrophoretically. With the conditions described by H. Weintraub and M Groudine [(1976) science, 193, 848-856], which we previously found to be selective in digesting actively transcribed regions in trout testis chromatin, a single chromosomal protein, H6, was solubilized. The nucleosomal histones and H1 remained insoluble, bound to the resistant DNA. In contrast, digestion with micrococcal nuclease led to a preferential solubilization of a second protein, HMG-T, together with the release of some nucleosomal histones and H1 into the soluble fraction. DNase II also discriminated between "active" and "inactive" chromatins; when a DNase II-solubilized "active" chromatin fraction was prepared, it too was enriched in H6 and HMG-T. Thus, both H6 and HMG-T, the two major low-salt extractable chromosomal nonhistone the two major low-salt extractable chromosomal nonhistone proteins from trout testis, are associated with chromatin regions selectively sensitive to nucleases. The preferential solubilization of HMG-T by micrococcal nuclease action suggests that it might be located at the internucleosomal "spacer" region.
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PMID:Selective association of the trout-specific H6 protein with chromatin regions susceptible to DNase I and DNase II: possible location of HMG-T in the spacer region between core nucleosomes. 26 31

When thymocytes are incubated with glucocorticoids at 37 degrees, 60--70% of the receptor bound steroid is associated with the nucleus. Under conditions where the rate of steroid-receptor formation is not limiting the transfer of steroid-receptors from the cytoplasm to the nucleus occurs rapidly with a T 1/2 of 30 seconds. These observations have led us to investigate whether or not all glucocorticoid receptor complexes are associated with the nucleus in the same manner. To this end, nuclear glucocorticoid-receptor complexes have been extracted by differential salt extraction and DNase I and DNase II digeston. Of the nuclear dexamethasone receptor complex initially bound, 70--75% is resistant to 0.2 M KCl extraction (designated N2) and 25--30% is resistant to 0.4 extraction (designated N4). N2 can be further extracted with 0.4 M KCl whereas N4 is resistant to reextraction with either 0.2 M KCl, suggesting that N2-N4 (N2-4) and N4 represent distinct physical forms of nuclear dexamethasone receptor. In intact cells, N2 and N4 differ under the following physiological condition. (1) N4 binding occurs prior to N2-4; (2) a cold chase of unlabeled dexamethasone decreases N2-4 by 70% but N4 binding by only 10%; (3) N4 binding decreases more rapidly than N2-4 following a decrease in hormone concentration by dilution; (4) a cold chase of either cortexolone or progesterone preferentially decreases N2-4 and has little effect on N4. In addition, the nuclear N2-4 and N4 distribution differ for cortisol, dexamethasone and triamcinolone acetonide, three steroids having different in vitro biological potencies. DNase I treatment of nuclei solubilizes approximately 60% of nuclear DNA yet releases only 20--30% of nuclear receptor, whereas DNase II solubilizes only 10% of nuclear DNA and releases 76--80% of nuclear receptor. As seen with salt extraction, the resistance of nuclear glucocorticoid-receptor complexes to a DNase I and II is dependent on the steroid molecule which is associated with the receptor. Of the steroids we have tested, nuclear triamcinolone acetonide and dexamethasone receptor complexes are most resistant to nuclease attack. Nuclear cortisol receptor complexes are readily solubilized by either DNase I or II under conditions where little dissociation of steroid from receptor occurs. These data represent evidence for physiologically distinct forms of nuclear glucocorticoid receptor interaction. In addition, they demonstrate the importance of the steroid portion of the steroid receptor in directing the nature and/or location of steroid receptors within or on the nucleus.
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PMID:Heterogeneity of nuclear glucocorticoid receptor interactions. 47 92

Core histones (H2A, H2B, H3, and H4) are reconstituted by salt gradient dialysis with DNA molecules ranging in length from 177 bp down to 50 bp. While reconstituted particles containing 125 bp are very similar to native particles, those particles containing a single piece of shorter DNA tend to aggregate. The aggregation depends on the ionic strength and DNA length. The DNA placement on the histone core is not random as determined by pancreatic DNase I digestions of particles containing 32P 5'-end-labeled DNA. Rather, it is found that all DNA molecules, up to 161 bp in length, reassociate with core histones in such a way as to produce defined patterns of DNase I cutting with respect to the 5' ends. Particles were made that contained two pieces of 65-bp DNA. These particles are very similar to native particles under most conditions but tended to dissociation results in the production of two half-nucleosomes (hemisones).
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PMID:Nucleosome reconstitution: effect of DNA length on nuclesome structure. 47 61

A small proportion (0.1-0.5%) of the total DNA content of native Chinese hamster metaphase chromosomes is protected from nucleolytic degradation following the removal of histones by extraction with either 0.2 N HCl or 2 M NaCl, and remains attached to the nonhistone protein core. Acid extraction followed by DNase I digestion leads to small fragments of 10-30 bases. Salt extraction followed by micrococcal nuclease digestion gives approx. 140 b.p. fragments which are undistinguishable in size from nucleosome core DNA fragments. Furthermore, DNase I treatment of salt extracted chromosomes gives DNA fragments containing single strands which are multiples of 10 bases in length, again characteristic of the nucleosome structure. Reassociation kinetics using the 32P-labelled 140 b.p. fragments as probes suggests they are enriched for rapidly reassociating sequences.
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PMID:A partial characterization of DNA fragments protected from nuclease degradation in histone depleted metaphase chromosomes of the Chinese hamster. 49 44

Chicken reticulocyte (polychromatic primitive erythrocyte) and erythrocyte chromatin was fractionated by ultrasound shearing and salt precipitation into three fractions differing in their activities to support the in vitro RNA synthesis. The transcriptionally active fraction of chicken reticulocyte chromatin which represented only about 0.5% of the total nuclear DNA contained essentially all the chromatin-associated endogenous RNA. Approximately 2% of this endogenous reticulocyte RNA hybridized to globin cDNA probe and could be translated in vitro into polypeptides which coelectrophoresed with the in vitro translation product of isolated chicken globin mRNA or chicken globin marker. Each of the three fractions had a characteristic distribution of chromosomal proteins and endogenous RNA. Polyacrylamide gel electrophoresis of the chromosomal proteins showed differences in their distribution among individual fractions of the same cell type and among corresponding fractions of reticulocyte or erythrocyte chromatin. Antisera produced against dehistonized reticulocyte chromatin were specific for reticulocyte but not erythrocyte chromatin. When reacted with each of the differentially templating chromatin fractions, it was found that reticulocyte-specific antibodies were highly reactive with the template-active fraction of reticulocytes, but essentially nonreactive with any other reticulocyte fraction. This same antiserum was not significantly reactive toward any erythrocyte fraction. The antigenicity of the template-active fraction of reticulocytes was abolished after pronase or DNase II digestion, but only partially diminished after DNase I digestion.
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PMID:Immunological properties of fractionated avian erythroid nuclei. 67 Feb 33

n-Butyrate treatment of growing Hela cells produces a dramatic increase in the levels of histone acetylation. We have exploited this system to study the effect of histone acetylation on chromatin structure. Chromatin containing highly acetylated histones is more rapidly digested to acid-soluble material by DNase I, but not by micrococcal nuclease. The same pattern of nuclease sensitivity was exhibited by in vitro-assembled chromatin consisting of SV40 DNA Form I and the 2 M salt-extracted core histones from butyrate-treated cells. Using this very defined system, it was possible to demonstrate that acetylated nucleosomes do not have a greatly diminished stability. Stability was measured in terms of exhange of histone cores onto competing naked DNA or sliding of histone cores along ligated naked DNA. Finally, it was shown that acetylated nucleosomes are efficient inhibitors of in vitro RNA synthesis by the E. coli holoenzyme as well as by the mammalian polymerases A and B.
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PMID:Effect of histone acetylation on structure and in vitro transcription of chromatin. 72 94

Chromatin core particles, containing 140 base pairs (bp) of DNA plus the inner histones, can be nearly quantitatively formed either by reassociation from 2 M NaCl or by reconstitution from salt extracted histones and DNA. The reassociated or reconstituted particles appear to be identical with the native particles in all physical properties examined (sedimentation velocity, histone content, circular dichroism, and melting) as well as in their patterns of digestion by micrococcal nuclease, DNase I, and trypsin. In the presence of excess DNA, no "half-particles" are formed. In the presence of excess histone, aggregated structures are formed in addition to 11S core particles.
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PMID:Reconstitution of chromatin core particles. 92 32

Nuclear matrix from HeLa cells was gently extracted with a high salt solution and treated with DNase I. DNA that remained associated with the nuclear matrix (N. M. DNA) and DNA fragments released into the supernatant (SN.DNA) were isolated respectively and dot hybridized to human telomere sequence (AGGGTT/TCCCAA)40 probe. As the time of DNase I treatment was extended, the amount of N. M. DNA decreased while the concentration of telomere sequence in N.M. DNA proportionally increased. These preliminary results suggest that the telomere sequence is tightly bound to nuclear matrix in HeLa cells.
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PMID:[Association of chromosomal telomere DNA with nuclear matrix in HeLa cells]. 141 28


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