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)

Several lines of evidence indicate that a component of axonemes from Chlamydomonas flagella is similar to actin from rabbit skeletal muscle. The polypeptide has an apparent molecular weight of 42,000 and in a pH gradient has the electrophoretic behavior of beta-actin. It was co-polymerized with rabbit actin and purified by affinity chromatography on DNase I-Sepharose. Incomplete proteolysis of mixed 35S-labeled axonemal protein and cold rabbit actin formed similar sets of peptides as analyzed by one-dimensional gel electrophoresis. The actin-like protein and the tubulin appear to be present in the axoneme in the molar ratio 1:60.
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PMID:An actin-like protein is a component of axonemes from Chlamydomonas flagella. 42 78

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

The fission yeast pap1+ gene encodes an AP-1-like transcription factor that contains a leucine zipper motif. We identified a target gene of pap1, the p25 gene. The 5' upstream region of the p25 gene contains an AP-1 site, and by DNase I footprint analysis, we showed that the pap1 protein binds to the AP-1 site as well as to a 14-bp palindrome sequence. p25 is overproduced when the pap1+ gene is overexpressed, whereas p25 is not produced at all in the pap1 deletion mutant. p25 was previously found to be overproduced in strains carrying cold-sensitive crm1 mutations whose gene product is essential for viability and is thought to play an important role in maintenance of a proper chromosomal architecture. Deletion and site-directed mutagenesis of sequences upstream of the p25 gene demonstrated that the AP-1 site as well as the palindrome sequence are crucial for transcriptional activation either by pap1 overproduction or by the cold-sensitive crm1 mutation; pap1+ is apparently negatively regulated by crm1+. Moreover, we found that cold-sensitive crm1 mutations are suppressed by the deletion of pap1+, further indicating a close relationship between crm1+ and pap1+. The crm1 protein is highly conserved; the budding yeast homolog, CRM1, which complements the fission yeast cold-sensitive crm1 mutation, was isolated and found to also be essential for viability. These results suggest the functional importance of chromosome structure on the regulation of gene expression through the pap1 transcription factor.
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PMID:Fission yeast pap1-dependent transcription is negatively regulated by an essential nuclear protein, crm1. 144 80

The mitochondrial uncoupling protein gene is rapidly induced in mouse brown fat following cold exposure. To identify cis-regulatory elements, approximately 50 kb of chromatin surrounding the uncoupling protein gene was examined for its hypersensitivity to DNase I. Seven DNase I-hypersensitive sites were identified in the 5'-flanking DNA, and one site was identified in the 3'-flanking DNA. Transgenic mice with an uncoupling protein minigene were generated by microinjection of fertilized eggs with a transgene containing 3 kb of 5'-flanking DNA and 0.3 kb of 3'-flanking DNA. Expression of the transgene is restricted to brown fat and is cold inducible. Four additional transgenic lines were generated with a second transgene containing a 1.8-kb deletion in the 5'-flanking DNA, and expression of this minigene is absent in all tissues analyzed. A DNase I-hypersensitive site located in the 1.8-kb deletion contains a cyclic AMP response element that binds a brown fat tumor enriched nuclear factor. On the basis of these observations, we propose that a cis-acting regulatory sequence between -3 and -1.2 kb of the 5'-flanking region, possibly at a DNase I-hypersensitive site, is required for controlling uncoupling protein expression in vivo.
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PMID:The mitochondrial uncoupling protein gene in brown fat: correlation between DNase I hypersensitivity and expression in transgenic mice. 171 3

This study was undertaken to determine if structural alterations of the bulk chromatin and the amount of protein associated with the nuclear matrix in cerebellar neurons depend on radiation dose and a cell's state of oxygenation. After irradiation with 2.5 to 25.0 Gy under both aerobic and anoxic conditions, the sensitivity of the neuronal chromatin to m. nuclease digestion increase linearly with dose up to about 5 Gy, beyond which there was no further increase. The same increase in accessibility of chromatin to micrococcal nuclease digestion was observed when neuronal nuclei were irradiated at 4 degrees C. Neuronal nuclei were stained with propidium iodide (PI) for DNA and with fluorescein isothiocyanate (FITC) for protein, both before and after complete digestion with DNase I, and analyzed by flow cytometry. There was no change in either the PI (P greater than 0.4) or the FITC (P greater than 0.9) fluorescence of undigested nuclei after irradiation. For the DNase I digested nuclei, the PI fluorescence was unchanged after irradiation (P greater than 0.4), but the FITC fluorescence increased significantly (P less than 0.02). This increase in the FITC fluorescence was linear with dose up to about 5 Gy, beyond which there was no further increase. The flow cytometry results from DNase I digested nuclei were identical for neurons irradiated under aerobic or anoxic conditions, indicating that this phenomenon is oxygen independent. This increase in FITC fluorescence after irradiation was inhibited at ice-cold temperatures and probably reflects an increase in protein content at the nuclear matrix that requires metabolism. This may explain our previously observed resistance of nuclear matrix-associated DNA to digestion by DNase I. This protein increase at the nuclear matrix appears to follow "saturation" kinetics identical to that previously reported for repair of DNA strand breaks in cerebellar neurons. However, the exact molecular nature of this process and its role in DNA repair or cell survival remains to be determined.
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PMID:Alterations of neuronal nuclear matrix and chromatin structure after irradiation under aerobic and anoxic conditions. 275 10

To study chromatin structure at the sites of DNA replicated in permeable cells, deoxyribonuclease I (DNase I) sensitivity of newly replicated DNA in permeable mouse sarcoma cells was compared with that of newly replicated DNA in intact cells. About 35% of the DNA replicated in permeable cells was hypersensitive to DNase I, and the remaining DNA showed the same DNase I sensitivity as that of parental chromatin DNA. The sensitivity of DNA replicated in permeable cells was higher than that of DNA newly replicated in intact cells, and was close to that of DNA replicated in the presence of cycloheximide. The sensitivity of DNA pulse-labeled with [3H]deoxythymidine triphosphate by replication in permeable cells was reduced significantly by chasing with cold deoxythymidine triphosphate. The present results suggest that chromatin structure at the sites of DNA replicated in permeable cells is similar to that at the sites of DNA replicated in living cells in the absence of protein synthesis, and that some structural change (possibly toward the maturation) of newly replicated chromatin occurs after the DNA replication in permeable cells.
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PMID:Deoxyribonuclease I sensitivity of DNA replicated in permeable mouse sarcoma cells. 376 2

The protein content of sympathetic neurones explanted from 10-11-day old chick embryos into culture medium containing nerve growth factor (NGF) increases steadily from about 100 to about 400 pg/cell in 7 days. Actin remains at close to 5% of the total protein during this period, but the proportion of unpolymerized actin falls. As measured by the inhibition of DNase I activity, rounded neurones without neurites contain 70 +/- 7% of their total actin in monomeric form, whereas cells in mature, neurite-bearing cultures contain 39 +/- 7%. When allowance is made for the increase in size of the neuronal cell bodies, the actin present in the neurites ('axons') alone is found to be almost entirely in filamentous form. Cultures exposed to radioactive leucine rapidly incorporate radioactivity into both sedimentable and non-sedimentable forms of actin. Actin-specific activities in the two fractions--estimated after isolation of the actin on small DNase I--Sepharose affinity columns--are similar after labelling for less than 1 h. Direct incorporation of newly-synthesized actin into filaments is suggested from these results. Pulse-chase experiments show that non-sedimentable protein in cultured sympathetic neurones turns over more rapidly than sedimentable protein. However, this is not true for actin, which shows a similar specific activity in sedimentable and non-sedimentable forms--even after 6 days of cold chase. This anomalous behaviour is simply explained by an exchange of actin molecules between filamentous and non-filamentous forms. Control experiments indicate that exchange does not occur to this degree during preparation of subcellular fractions. It is consequently attributed to exchange processes in the living cell.
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PMID:Actin polymerization and synthesis in cultured neurones. 622 55

Actin has been identified and purified partially from trophozoites of Entamoeba histolytica HMI-IMSS by a procedure that minimizes proteolysis. In cellular extracts, Entamoeba actin would copolymerize with muscle actin, but would not bind to DNase I or form microfilaments. Fractionation of the extracts by DEAE-cellulose and Sephadex G-150 chromatography yielded a purified actin that would copolymerize with rabbit skeletal muscle actin or polymerize alone into long filaments at 24 degrees C upon addition of 100 mM KC1 and 2 mM MgCl2. These filaments are not cold-stable and will depolymerize at 4 degrees C in 1 or 2 h. Entamoeba actin filaments bind phallotoxin with the same affinity as muscle actin and decorate with rabbit skeletal muscle heavy meromyosin. Entamoeba actin filaments activate the Mg2+ ATPase of heavy meromyosin to the same Vmax as muscle actin, but the Kapp is 2.8 times higher. Entamoeba actin is a single species with a slightly higher molecular weight than muscle actin (45,000) and a more acidic pI (5.4). The purified actin does not bind to DNase I, produce inhibition of the enzymatic activity, or block the binding of muscle actin. Comparison of the peptides obtained by limit digest with protease V8 from Staphylococcus aureus shows sequences with common mobility between alpha-actin and Entamoeba actin, but additional peptides are present which may account for the different properties of the Entamoeba actin. Finally, in vitro translation of mRNA from trophozoites produces a single polypeptide equivalent to the molecule purified from Entamoeba extracts.
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PMID:Isolation and characterization of actin from Entamoeba histolytica. 630 64

Escherichia coli protein CS7.4 (CspA), homologous to the class of eukaryotic Y-box DNA-binding proteins, is a cold shock transcriptional activator of at least two genes, hns and gyrA. It was demonstrated that all or nearly all the elements necessary for the stimulation of hns transcription by CS7.4 protein are located in the proximal 110 bp DNA fragment of this gene with no additional elements being present in a longer fragment (660 bp) extending further upstream from the hns promoter. Protein CS7.4 bound strongly to the 110 bp segment of the hns promoter in crude extracts of cold shocked cells, but the purified protein displayed a weak interaction with the same DNA fragment. Purified CS7.4 protein also caused increased or decreased accessibility to DNase I at different sites of the 110 bp fragment of hns but the majority of these effects was seen only in the presence of RNA polymerase. Since gel shift experiments showed that protein CS7.4 stimulated the binding of RNA polymerase to the promoter of hns and since it is known that there are similarities between CS7.4 and ssDNA-binding proteins, we suggest that formation of the open complex by the RNA polymerase or protein-protein contacts between CS7.4 and the RNA polymerase are prerequisites for and/or the effects of the interaction of CS7.4 with its DNA target. The presence of a conserved CCAAT element in the hns promoter region, on the other hand, was found not to be stringently required for cold shock activation since expression of E coli of an hns-cat fusion containing the Proteus vulgaris hns promoter lacking a CCAAT box increased over four-fold after cold shock.
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PMID:Interaction of the main cold shock protein CS7.4 (CspA) of Escherichia coli with the promoter region of hns. 774 32

High concentrations of Tris are effective in dissociating actin-containing complexes, such as the red cell membrane cytoskeleton. A preparative procedure for red cell actin is based on the dissociation of the membrane skeletal complex in a buffer containing 1 M Tris hydrochloride, followed by gel filtration chromatography in the same medium. The actin is recovered as the monomer and is fully native, as judged by its critical concentration of polymerization, inhibition of DNase I, stimulation of myosin ATPase, and the appearance in the electron microscope of filaments, both bare and decorated with heavy meromyosin, and of magnesium ion-induced paracrystals. The Tris solution causes rapid depolymerization of F-actin with no denaturation, and the solution of monomeric actin in this medium is stable for many weeks in the cold; concentrated Tris is more reliable than guanidinium chloride for the depolymerization of F-actin in the estimation of total actin concentration by the DNase I inhibition assay.
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PMID:Concentrated Tris solutions for the preparation, depolymerization, and assay of actin: application to erythroid actin. 776 94


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