Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.22.1 (DNase II)
 429 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The action of micrococcal nuclease, DNase I and DNase II on mouse TLT hepatoma chromatin revealing the periodicity of its structure as visualized by denaturing and non-denaturing gel electrophoresis, was consistent with the action of these enzymes on other chromatins. Micrococcal nuclease showed a complex subnucleosome fragment pattern based on multiples of 10 base pairs with a prominant couplet at 140/160 base pairs and the absence of the 80 base pair fragment. This couplet of the core and minimal nucleosome fragments was conspicuously present in the mononucleosomes found in the 11S fractions of a glycerol gradient centrifugation. DNase I and II produced a fairly even distribution of a 10 base pair increasing series of fragments to about 180 base pairs, a pattern also repeated in the DNA of nucleosome glycerol-gradient fractions. In limited digestions by these nucleases multinucleosomic DNA fragments are pronounced. These fragment lengths are multiples of an estimated average repeat length of nucleosome DNA of 180 base pairs. The action of the endogenous Mg/Ca-stimulated endonuclease produced only limited cuts in the hepatoma chromatin resulting primarily in multi-nucleosomic DNA fragment lengths and only upon lengthy digestion limited subnucleosomic, 10-base-pair multiple fragments are produced. The putative euchromatin-enriched fractions (50-75S) of the glycerol gradient centrifugation of autodigested chromatin, similarly, contained primarily the multinucleosomic DNA fragment lengths. These results are consistent with our previous electron microscopic demonstration that autodigested chromatin as well as the putative euchromatin-enriched fractions were composed of multi-nucleosomic chromatin segments containing a full complement of histones.
Mol Cell Biochem 1978 Apr 11
PMID:Periodicity and fragment size of DNA from mouse TLT hepatoma chromatin and chromatin fractions using endogenous and exogenous nucleases. 20 20

As a first step in studies on the molecular mechanism(s) underlying gentamicin toxicity, the effect of treating rats with this aminoglycoside antibiotic (100 mg/kg once or twice daily for 3 days) on the analytical subfractionation of the kidney cortex has been examined. DNA was used as a marker for the nuclei, cytochrome oxidase for mitochondria, acid phosphatase for lysosomes, catalase for peroxisomes (with reservations; see the companion paper), NADPH-cytochrome c reductase for the endoplasmic reticulum, p-nitrophenyl-alpha-mannosidase (at pH 5.5) for the Golgi apparatus, AMPase for the plasma membrane in general and alkaline phosphatase for the brush border, and lactate dehydrogenase for the cytosol. In addition, the presumptive lysosomal hydrolases N-acetyl-beta-D-glucosaminidase, p-nitrophenyl-alpha-mannosidase (at pH 4.5), cathepsin D, and DNase II were monitored. Electron microscopy was also performed on the subfractions obtained. The only significant biochemical changes brought about by gentamicin treatment were that N-acetyl-beta-D-glucosaminidase demonstrated both a greater total activity and a larger enrichment in the 104,000gav pellet, while p-nitrophenyl-alpha-mannosidase at pH 4.5 demonstrated the same total activity and a greater enrichment in the 104,000gav pellet. Since myeloid bodies were shown by electron microscopy to sediment primarily with the 500gav and 10,000gav pellets, the biochemical changes seen cannot be associated with these morphological structures. These findings suggest that selective changes in a certain subpopulation(s) of lysosomes or in certain lysosomal enzymes may be involved in the early stages of gentamicin toxicity. On the other hand, no lysosomal membrane damage was observed here, since both the latency of acid phosphatase and the recovery of this activity in the soluble cytosol were unchanged. The present investigation may also have relevance for the dosage and duration of gentamicin treatment chosen in clinical situations.
Exp Mol Pathol 1987 Apr
PMID:Biochemical effects of gentamicin on rat kidney cortex. II. Analytical subfractionation after short-term, high-dose treatment. 303 Aug

Chromatin structure of globin and ovalbumin genes in chicken erythrocyte nuclei has been investigated by means of the "nuclease criterion" (described earlier). In intact nuclei (i.e. in the presence of 3 mM MgCl2) DNase I cleaves chromatin of both genes generating fragments multiple of a double-nucleosome repeat (2N-periodicity). However, in the case of the globin gene, apart from the 2N-periodicity, fragments were observed that are multiple of 100 b.p. and are characteristic for partially unfolded chromatin. This distinction in nuclease cleavage patterns correlates with a higher sensitivity of the globin gene as compared with the inactive ovalbumin gene. At 0.5-0.7 mM MgCl2 the transition from dinucleosomal fragmentation with DNase I and DNase II to fragmentation via a 100 b.p. interval occurs and the difference in digestibility of both genes is dramatically increased. If chromatin has been decondensed by incubation of nuclei in 10 mM Tris-buffer DNase Il generates an usual nucleosomal repeat, and in this ionic conditions one may not observe any difference in nuclease sensitivity of the analyzed genes. The data allow to suggest that the high nuclease sensitivity of potentially active genes can be conditioned by more relaxed arrangement of nucleosomes in higher order chromatin structure.
Mol Biol (Mosk)
PMID:[Structural state of active and inactive genes during chromatin decondensation]. 318 36

It was revealed by means of nucleoprotein-celite-chromatography that DNA-protein interactions in the chromatin fraction sensitive to micrococcal nuclease and DNase II are weaker that in the resistant one. The micrococcal nuclease destroys the DNA-matrix bond resistant to salt-urea, while DNase II does not change the DNA-matrix integrity. Tightness of the DNA-protein interactions is weakened by the increasing chromatin fragmentation, but does not depend on the size of chromatin particles.
Mol Gen Mikrobiol Virusol 1988 Oct
PMID:[Stability of DNA-protein interactions in chromatin fractions with different sensitivity to nucleases]. 323 Dec 30

The contact points of transcription factor IIIA with the internal control region of the 5 S RNA gene of Xenopus have been investigated by probing the accessibility of the DNA in the protein-DNA complex to dimethylsulphate and to micrococcal nuclease. The results of quantitative measurements, combined with those from earlier DNase I and DNase II protection studies, are consistent with a series of multiple contacts about five base-pairs apart, or half a double-helical turn, along the whole length of the internal control region. The nine patches of contact we have mapped could correspond to nine DNA-binding fingers in the protein. A model for the overall geometry of the interaction is presented in which the protein lies on one face of the DNA double helix.
J Mol Biol 1986 Dec 05
PMID:Mapping of the sites of protection on a 5 S RNA gene by the Xenopus transcription factor IIIA. A model for the interaction. 356 Feb 27

The process of chromatin compactization in nuclei at different concentrations of Mg2+ and/or Na+ ions has been investigated by analysis of chromatin cleavage pattern with DNase II. Nuclei of cells that differ in transcriptional activity and have different nucleosome DNA repeat length such as pigeon erythrocytes, rat cerebellum neurons and pigeon brain cortex neurons were studied. In the presence of 0-3 mM MgCl2 several compactization levels of nucleosomal fiber were revealed in chromatin of pigeon erythrocyte and rat cerebellum nuclei (nucleosome DNA repeat of 210 +/- 3 and 202 +/- 3 nucleotide pairs, respectively). Each of these levels are characterized by different types of periodical DNA fragmentation of chromatin with DNase II, namely formation of nucleosomal, "half-nucleosomal" (fragmentation via a 100 nucleotide pairs interval), and dinucleosomal periodicities. Similar compactization stages were shown also for isolated erythrocyte chromatin. In 0-3 mM MgCl2 chromatin of pigeon brain cortex neuron nuclei having nucleosome DNA repeat size 164 +/- 3 nucleotide pairs is cleaved with DNase II producing only a "half-nucleosomal" periodicity. A pattern of chromatin fragmentation was compared in the presence of Na+ and Mg2+ ions. In the presence of 10-100 mM NaCl or in 0.1-3 mM MgCl2 but in the presence of 50 mM NaCl erythrocyte chromatin condenses in nuclei forming a structure which is characterized only by a "half-nucleosomal" periodicity of fragmentation at DNase II action. Upon higher NaCl concentration (100-400 mM) in the presence of 3 mM MgCl2 a transition from dinucleosomal fragmentation to nucleosomal fragmentation of erythrocyte chromatin in nuclei with DNase I was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Biol (Mosk)
PMID:[Structural organization of the nucleosomal chromatin fibril under various ionic conditions]. 380 10

The positions and relative frequencies of the primary cleavages made by micrococcal nuclease on the DNA of nucleosome core particles have been found by fractionating the double-stranded products of digestion and examining their single-stranded compositions. This approach overcomes the problems caused by secondary events such as the exonucleolytic and pseudo-double-stranded actions of the nuclease and, combined with the use of high resolution gel electrophoresis, enables the cutting site positions to be determined with a higher precision than has been achieved hitherto. The micrococcal nuclease primary cleavage sites lie close (on average, within 0.5 nucleotide) to those previously determined by Lutter (1981) for the nucleases DNase I and DNase II. These similarities show that the accessible regions are the same for all three nucleases, the cleavage sites being dictated by the structure of the nucleosome core. The differences in the final products of the digestion are explained in terms of secondary cleavage events of micrococcal nuclease. While the strongly protected regions of the nucleosome core DNA are common to all three nucleases, there are differences in the relative degrees of cutting at the more exposed sites characteristic of the particular enzyme. In particular, micrococcal nuclease shows a marked polarity in the 3'-5' direction in the cutting rates as plotted along a single strand of the nucleosomal DNA. This is explained in terms of the three-dimensional structure of the nucleosome where, in any accessible region of the double helix, the innermost strand is shielded by the outermost strand on the one side and the histone core on the other. The final part of the paper is concerned with the preference of micrococcal nuclease to cleave at (A,T) sequences in chromatin.
J Mol Biol 1983 Oct 25
PMID:Location of the primary sites of micrococcal nuclease cleavage on the nucleosome core. 663 65

Chromatin from myeloma cells RPC5 and ABPC22, and from spleen and liver cells of immunized rats and mice, and mice bearing tumours, was fractionated into three part: 0.35 M NaCl-soluble, 2 M NaCl-soluble and residual. The residual fraction from myeloma cells differed from that of immunized spleen cells, described previously as containing unique sequences (5), in that it has higher protein and DNA levels, lower DNase II sensitivity and lower template activity.
Mol Cell Biochem 1982 Oct 18
PMID:Differences in salt solubility, DNase II sensitivity and template activity of chromatin from antibody synthesizing spleen cells and myeloma cells RPC 5 and ABPC 22. 689 Jun 25

Myocyte apoptosis increases with age in Fischer 344 rats, but the multiple molecular events implicated in this phenomenon remain to be identified. Several defects involving Ca2+ homeostasis, pH, and the expression of p53 and genes of the Bcl-2 protein family may contribute to the activation of myocyte death. Therefore, changes in intracellular pH, cytosolic Ca2+, DNase I and DNase II were measured in myocytes isolated by enzymatic digestion from rats of different ages. Moreover, the expression of p53, Bcl-2 and Bax in these cells was determined. Measurements of intracellular pH by BCECF fluorescence at 3, 12 and 24 months showed that this parameter did not change with age: 3 months, 7.20+/-0.05; 12 months, 7.21+/-0.07; 24 months, 7.18+/-0.09. In contrast, diastolic Ca2+ determined by the Fura 2-AM method increased progressively from 99.8+/-1.9 nm at 3 months to 136.3+/-9.6 nm at 24 months (P<0.001). Concurrently, DNase I activity evaluated by plasmid digestion assay in myocytes increased 3.2-fold from 3 to 24 months (P<0.02). Conversely, pH-dependent-DNase II remained essentially constant with age. Western blotting performed on ventricular myocytes did not detect significant changes in p53, Bax and Bcl-2 proteins with age. Similarly, immunocytochemically, the fraction of myocytes labeled by p53, Bax and Bcl-2 did not change from 3 to 24 months. In conclusion, myocyte aging is characterized by an increase in diastolic calcium which may activate DNase I triggering apoptosis, independently from the expression of p53, Bax and Bcl-2 in the cells.
J Mol Cell Cardiol 1998 Mar
PMID:Intracellular calcium, DNase activity and myocyte apoptosis in aging Fischer 344 rats. 951 29

The most widely recognized biochemical change associated with the majority of apoptotic systems is the degradation of genomic DNA. Among the enzymes that may participate in this cleavage, the acidic cation-independent DNase II is a likely candidate since it is activated in many apoptotic cells. To better understand its role, we purified and sequenced a DNase II extracted from porcine spleen. Protein sequencing of random peptides demonstrated that this enzyme is derived from a ubiquitous serpin, the leukocyte elastase inhibitor (LEI), by an acidic-dependent posttranslational modification or by digestion with elastase. We call this novel enzyme L-DNase II. In vitro experiments with purified recombinant LEI show that the native form has no effect on purified nuclei whereas its posttranslationally activated form induces pycnosis and DNA degradation. Antibodies directed against L-DNase II showed, in different cell lines, an increased expression and a nuclear translocation of this enzyme during apoptosis. Since the appearance of the endonuclease activity results in a loss of the anti-protease properties of LEI, the transformation from LEI to L-DNase II may act as a switch of protease and nuclease pathways, each of which is activated during apoptosis.
Mol Cell Biol 1998 Jun
PMID:L-DNase II, a molecule that links proteases and endonucleases in apoptosis, derives from the ubiquitous serpin leukocyte elastase inhibitor. 958 2


1 2 3 Next >>