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

Flanagan, John F. (Duke University School of Medicine, Durham. N.C.). Hydrolytic enzymes in KB cells infected with poliovirus and herpes simplex virus. J. Bacteriol. 91:789-797. 1966.-The effect of poliovirus and herpes simplex virus infection on the activity of five hydrolytic enzymes was studied in tissue culture cells of KB type. During the course of poliovirus infection, the activity of beta-glucuronidase, acid protease, acid ribonuclease, acid deoxyribonuclease, and acid phosphatase in the cytoplasm rose to levels two- to fourfold greater than the activity present in the cytoplasm of uninfected cells. The rise in cytoplasmic activity was accompanied by a concomitant decrease in enzymatic activity bound to cell particles. Shift of enzymatic activity from the particulate to soluble state was first detected at 6 hr after poliovirus infection, coinciding with the appearance of new infectious particles and virus cytopathic effect. No net synthesis of these enzymes after poliovirus infection was found. Hydrocortisone added to the culture medium failed to affect either the titer of virus produced in the cells or the release of hydrolytic enzymes from the particulate state. Herpes simplex infection produced minimal alterations in the state of these enzymes in KB cells. It is hypothesized that the breakdown of lysosomes and release of hydrolytic enzymes accompanying poliovirus infection is produced by alterations in cell membrane permeability during the course of virus replication and by the consequent change in the ionic content of the cell sap.
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PMID:Hydrolytic enzymes in KB cells infected with poliovirus and herpes simplex virus. 428 87

Homogenates of HeLa cells contain neuraminidase activity. This enzyme is particle-bound, and it has a pH optimum of 4.2. Hydrocortisone-regulated cells contain two to three times as much neuraminidase as the corresponding controls. The hydrocortisone treatment also causes an increase in the cell content of beta-glucuronidase and acid deoxyribonuclease.
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PMID:Neuraminidase activity in hela cells: effect of hydrocortisone. 547 38

The effects of steroid-induced modifications of chromatin structure on the extent and sites of chloroethylnitrosourea binding to chromatin were studied using log-phase HeLa cells. The cells were exposed to 0.1 to 2.0 microM hydrocortisone for 22 hr; this resulted in depressed DNA synthesis while transcriptional activity was stimulated. Hydrocortisone had no effect upon cellular or nuclear uptake of the two nitrosoureas under study, 0.6 mM chlorozotocin or 1-(2-chloroethyl-3-cyclohexyl-1-nitrosourea). Both drugs were found to alkylate transcriptional chromatin preferentially, as demonstrated by DNase II and DNase I digestion. This alkylation was stimulated 2-fold by the same micromolar concentrations of hydrocortisone, 0.1 to 2.0 microM, which stimulated transcription. The extent of nuclear RNA alkylation, determined using RNase T2 as a probe, was found to contribute less than 20% of total chromatin alkylation and was unaffected by steroid pretreatment. Instead, the increased alkylation within these chromatin subfractions was attributed to a steroid-induced alteration of chromatin structure. Electron microscopic examination of HeLa nuclear morphology revealed a hydrocortisone-induced disaggregation of nuclear membrane-associated heterochromatin resulting in a more heterogeneous, less condensed distribution of chromatin. Such data are consistent with a relaxation of the supercoiled chromatin structure, resulting in increased transcription and increased accessibility of potential target sites for nitrosourea alkylation.
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PMID:Influence of hydrocortisone on the binding of nitrosoureas to nuclear chromatin subfractions. 743 52

In the present study, we undertook kinetic analyses of DNA degradation and acid DNase activity in murine thymus after administration of hydrocortisone. Hydrocortisone induced apoptosis in thymocytes, and a large number of cortical thymocytes became TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labelling)-positive (TUNEL+). F4/80+ macrophages infiltrated through the cortico-medullay junction into the cortical region, and thereafter engulfed apoptotic cells in the cortex of thymus. The distribution of acid DNase-active cells appeared to be similar to that of F4/80+ macrophages. Eighteen hours after the injection, although the foci of apoptotic cells were situated within massively distended F4/80+ macrophages, oligonucleosomal DNA fragments on an agarose gel were undetectable. Our results showed that macrophages were involved in the disappearance of oligonucleosomal DNA fragments in apoptotic thymocytes. Taken together, macrophages play a role in the hydrolysis of DNA in apoptotic cells upon their phagocytosis of the dead cells.
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PMID:Macrophages are involved in DNA degradation of apoptotic cells in murine thymus after administration of hydrocortisone. 1184 Jan 61