scholarly journals Deoxyribonucleic acid-dependent ribonucleic acid polymerase activity in rat liver after protein restriction

1975 ◽  
Vol 148 (1) ◽  
pp. 49-56 ◽  
Author(s):  
G M Andersson ◽  
A von der Decken
Keyword(s):  
Rna Polymerase ◽  
Dietary Protein ◽  
Deoxyribonucleic Acid ◽  
Specific Activity ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
High Quality ◽  
Sephadex Column ◽  
High Quality Protein ◽  
Polymerase I

Rats were fed for 6 days on a diet containing either 3 or 20% high-quality protein. Nuclei were isolated from liver and DNA-dependent RNA polymerases (EC 2.7.7.6) extracted with 1 M-(NH4)2SO4. The proteins were then precipitated with 3.5 M-(NH4)2SO4 and after dialysis applied to a DEAE-Sephadex column. The column was developed with a gradient of (NH4)2SO4. Polymerase I separated well from α-amanitin-sensitive polymerase II. The enzyme activities were compared between the two dietary groups. Rats that had received 3% protein showed a lower polymerase I activity per g wet wt. of liver, per mg of DNA and per mg of protein. Polymerase II was lower in activity per g wet wt. of liver and per mg of DNA, but was higher per mg of protein. Polyacrylamide-gel electrophoretograms showed a higher proportion of contaminating proteins in polymerase II fractions isolated from 20%-protein-fed rats. The data explain the lower activity obtained per mg of protein in these rats. It is concluded that a decrease in dietary protein content from 20 to 3% induces a fall in content and specific activity of RNA polymerase I and II in liver.

scholarly journals Nuclear binding of progesterone in chick oviduct. Multiple binding sites in vivo and transcriptional response

1976 ◽  
Vol 156 (2) ◽  
pp. 391-398 ◽  
Author(s):  
T C Spelsberg
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Binding Sites ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Target Tissue ◽  
Functional Sites ◽  
Nuclear Binding ◽  
Polymerase I

1. Varied doses of labelled or unlabelled progesterone were injected into immature chicks which had previously been stimulated with oestrogen. The concentrations of nuclear bound [3H]progesterone were correlated with the effects of the hormone on endogenous RNA polymerase I and II activities in isolated oviduct nuclei. 2. The extent of nuclear localization of [3H]progesterone in oviduct (a progesterone target tissue) was shown to be much greater than in lung (non-target tissue). The conccentration of bivalent cations in solvents used in the nuclei isolations has a marked effect on the amount of bound hormone in the nuclei. 3. Evidence for the existence of several classes of binding sites for progesterone in the oviduct nuclei is given. These classes represent about 1000) 10000 and 100000 molecules of the hormone per cell nucleus and are saturated by injecting approx. 10, 100 and 1000 mug of progesterone respectively. 4. When saturation of the first (highest affinity) class of nuclear sites occurs, a marked inhibition in RNA polymerase II (but not RNA polymerase I) activity was observed. When the second class of sites was saturated, alterations in both RNA polymerase I and II activities were observed. Binding to the third class of nuclear binding sites was not accompained by further changes in polymerase activity. It is suggested that the first two classes of nuclear binding sites may represent functional sites for progesterone action in the chick oviduct.

scholarly journals MxA GTPase Blocks Reporter Gene Expression of Reconstituted Thogoto Virus Ribonucleoprotein Complexes

2000 ◽  
Vol 74 (1) ◽  
pp. 560-563 ◽  
Author(s):  
Friedemann Weber ◽  
Otto Haller ◽  
Georg Kochs
Keyword(s):  
Rna Polymerase ◽  
Inhibitory Effect ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Wild Type ◽  
Transfected Cells ◽  
Ribonucleoprotein Complexes ◽  
Polymerase I ◽  
Cellular Compartments ◽  
Antiviral Mechanism

ABSTRACT Human MxA protein accumulates in the cytoplasm of interferon-treated cells and inhibits the multiplication of several RNA viruses, including Thogoto virus (THOV), a tick-borne orthomyxovirus that transcribes and replicates its genome in the cell nucleus. The antiviral mechanism of MxA was investigated by using two alternative minireplicon systems in which recombinant viral ribonucleoprotein complexes (vRNPs) of THOV were reconstituted from cloned cDNAs. A chloramphenicol acetyltransferase reporter minigenome RNA was expressed either by T7 RNA polymerase in the cytoplasm of transfected cells or, alternatively, by RNA polymerase I in the nucleus. The inhibitory effect of MxA was studied in both cellular compartments by coexpressing wild-type MxA or TMxA, an artificial nuclear form of MxA. Our results indicate that both MxA proteins recognize the assembled vRNP rather than the newly synthesized unassembled components. The present findings are consistent with previous data which indicated that cytoplasmic MxA prevents transport of vRNPs into the nucleus, whereas nuclear MxA directly inhibits the viral polymerase activity in the nucleus.

scholarly journals Estrogen-induced modification of uterine RNA polymerase activity depends on localization of the estrogen receptor

2007 ◽  
Vol 59 (2) ◽  
pp. 105-112
Author(s):  
Zorica Zakula ◽  
Esma Isenovic ◽  
Mojca Stojiljkovic ◽  
G. Koricanac ◽  
Snezana Tepavcevic ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Female Rats ◽  
Cytosol Fraction ◽  
Ovx Rats ◽  
Rna Polymerase Activity ◽  
Polymerase I

The aim of this study was to examine the effects of estradiol (E2) on activity of RNA polymerase I and RNA polymerase II in uterine nuclei of ovariectomized (OVX) female rats. The obtained results show that estrogen-receptor (E-R) complexes in 30 min induced an increase of polymerase II activity. A second increase of polymerase II activity was observed after 3 h-incubation of nuclei with the E-R complex formed in the cytosol fraction. However, activity of polymerase I was increased 2 h after the start of incubation, with highest activity detected at 3 h in nuclei incubated with E-R complexes. On the contrary, no stimulatory effect on either polymerase I or polymerase II activity was observed in nuclei incubated with E2 alone. These results indicate that E2 stimulates the cytosolic estrogen receptor (ER), which in turn causes uterotrophic responses in OVX rats. In addition, they suggest that in order to provoke uterotrophic responses E-R complexes formed in the cytosol need to be retained in the nucleus for a longer period of time. .

scholarly journals NAD+, ADP-ribosylation and transcription in permeabilized mammalian cells

1981 ◽  
Vol 199 (3) ◽  
pp. 813-817 ◽  
Author(s):  
J Walker ◽  
C K Pearson
Keyword(s):  
Rna Polymerase ◽  
Mammalian Cells ◽  
Inhibitory Effect ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Permeabilized Cells ◽  
Adp Ribosylation ◽  
Deoxyribonuclease I ◽  
Rna Polymerase Activity ◽  
Polymerase I

When permeabilized hamster fibroblasts were incubated with 4 mM-NAD+, the substrate for poly(ADP-ribose) polymerase, RNA polymerase I activity was inhibited by about 85%. This inhibition was not relieved by prior incubation of cells with 3-aminobenzamide, a potent inhibitor of the poly(ADP-ribose) polymerase. Digestion of cells with pancreatic deoxyribonuclease I resulted in the inhibition of RNA polymerase I by 80% and the activation of poly(ADP-ribose) polymerase by up to 300%; prior incubation with 3-aminobenzamide did not prevent the inhibition of the RNA polymerase activity. No radioactivity was found associated with RNA polymerase I during later stages of purification of this enzyme from permeabilized cells previously incubated with [14C]NAD+. The inhibitory effect of NAD+ on RNA polymerase I was not specific for NAD+, as other small, negatively charged molecules with a nuclear location also inhibited the enzyme. The results do not support the concept of a role for ADP-ribosylation in transcription catalysed by RNA polymerase I.

scholarly journals Cloning the Horse RNA Polymerase I Promoter and Its Application to Studying Influenza Virus Polymerase Activity

Viruses ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 119 ◽  
Author(s):  
Gang Lu ◽  
Dong He ◽  
Zengchao Wang ◽  
Shudan Ou ◽  
Rong Yuan ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Polymerase I

Activity of purified and chromatin-associated mouse TLT hepatoma RNA polymerases on homologous whole chromatin and euchromatin-enriched segments isolated from homologous chromatin

1977 ◽  
Vol 55 (3) ◽  
pp. 227-238 ◽  
Author(s):  
Ralph J. Smith ◽  
Jacob D. Duerksen
Keyword(s):  
Rna Polymerase ◽  
Gradient Centrifugation ◽  
Distribution Patterns ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Glycerol Gradient ◽  
Rna Polymerase Activity ◽  
Gradient Fractionation ◽  
Polymerase I ◽  
Diffuse Distribution

The RNA polymerase (EC 2.7.7.6) activity of mouse TLT hepatoma nuclei is separable into three forms, I, IIA, and IIB; each of these partially purified enzymes demonstrates characteristics generally similar to those reported for these enzymes of other systems. All three forms of TLT hepatoma RNA polymerase show a considerable preference for single-stranded DNA. The full expression of the endogenous RNA polymerase activity of mouse TLT hepatoma chromatin is dependent on the salt concentration. No additional template activity to added RNA polymerase I or II is available. Physical shearing decreased endogenous RNA polymerase activity and increased template capacity to the added enzymes. Glycerol-gradient fractionation of physically sheared chromatin gave a fairly diffuse distribution of the endogenous RNA polymerase activity to the marginally euchromatin-enriched fractions. However, enzymatic shearing of TLT hepatoma chromatin by Mg,Ca-dependent autodigestion results in a distribution of endogenous RNA polymerase activity to the highly euchromatin-enriched fractions similar to that obtained for nascent RNA (Paul, I. J. &Duerksen, J. D. (1976) Biochem. Biophys. Res. Commun. 68, 97–105). The distribution patterns of template capacity determined with added RNA polymerase I and II differed somewhat from the above distributions and varied with the length of autodigestion. Shearing by autodigestion is preferred, and followed by glycerol-gradient centrifugation permits a considerable enrichment for euchromatic segments.

Temperature-Sensitive RNA Polymerase of a Mammalian Cell Mutant

1973 ◽  
Vol 12 (3) ◽  
pp. 839-845
Author(s):  
P. M. NAHA
Keyword(s):  
Rna Polymerase ◽  
Cell Line ◽  
Conclusive Evidence ◽  
Rna Polymerase I ◽  
Temperature Sensitive ◽  
Sephadex Column ◽  
Sensitivity Tests ◽  
Sensitive Factor ◽  
In The Wild ◽  
Polymerase I

In our attempts to characterize a temperature-sensitive mutant (ts-2) of monkey kidney cell line BSC-1, we have provided evidence to show that the mutant was defective in the synthesis or processing of rRNA (45, 28 and 18 s) molecules at 39·5°C and there was indication that the nucleolar RNA polymerase (I) or some factor associated with its functional activity was thermolabile at the restricted temperature of 39·5°C. The enzyme in the wild type cell line was, however, stable at this temperature. Though conclusive evidence to implicate RNA polymerase (I) was not obtained in these experiments, temperature-sensitivity tests with crude enzyme extracts of the RNA polymerase in ts-2 showed that it contained a temperature-sensitive factor which was either degraded rapidly or failed to be eluted out of the DEAE-Sephadex column. This temperature-sensitive factor was not affected by α-amanitin.

scholarly journals Transcriptionally active RNA polymerases from Morris hepatomas and rat liver. Elucidation of the mechanism for the preferential increase in the tumour RNA polymerase I

1980 ◽  
Vol 190 (3) ◽  
pp. 781-789 ◽  
Author(s):  
B W Duceman ◽  
S T Jacob
Keyword(s):  
Rna Polymerase ◽  
Tumour Growth ◽  
Rna Polymerases ◽  
Rna Polymerase I ◽  
Product Analysis ◽  
Sephadex Column ◽  
Tissue Homogenates ◽  
Enzyme Pattern ◽  
Polymerase I

The amount and/or activity of DNA-dependent RNA polymerase I, Ii and III from resting liver, regenerating liver and a series of Morris hepatomas (5123D, 7800, 7777, 3924A) were determined after extraction of the enzymes from whole tissue homogenates and subsequent fractionation by DEAE-Sephadex column chromatography. When compared with resting liver, the tumours exhibited a characteristic enzyme pattern in which polymerase I, but not II, was increased. The increase in RNA polymerase I was proportional to the tumour growth rates. Alterations in polymerase III were confined to the most rapidly proliferating hepatomas. By contrast, all classes of RNA polymerase were found to be increased during liver regeneration. Relative to resting liver, the fastest growing tumour, 3924A, exhibited the highest activities and/or amounts of RNA polymerase I (8-fold) and III (5-fold) per g of tissue. These alterations in the tumour RNA polymerases were reflected in corresponding increases in the transcriptionally active (bound or chromatin-associated) enzyme population. The mechanisms underlying the augmented synthesis of RNA in vitro by bound polymerase I from hepatoma 3924A were elucidated by product analysis. The results indicated that, relative to liver RNA polymerase I, the tumour enzyme produced more nascent RNA chains and elongated these chains at a faster rate. The number of 3'-termini, as measured by incorporation into uridine, was higher in the hepatoma even under conditions which prevented re-initiation. suggesting increased amount of transcriptionally active RNA polymerase I in the tumour.

scholarly journals New Model for the Yeast RNA Polymerase I Transcription Cycle

2001 ◽  
Vol 21 (15) ◽  
pp. 4847-4855 ◽  
Author(s):  
Pavel Aprikian ◽  
Beth Moorefield ◽  
Ronald H. Reeder
Keyword(s):  
Rna Polymerase ◽  
Transcription Initiation ◽  
Polymerase Activity ◽  
Rna Polymerase I ◽  
Rrna Synthesis ◽  
New Model ◽  
Pol I ◽  
Stable Association ◽  
Polymerase I ◽  
Novel Model

ABSTRACT Using an immobilized template assay, we observed two steps in assembly of the yeast RNA polymerase I (Pol I) preinitiation complex: stable binding of upstream activating factor (UAF) followed by recruitment of Pol I-Rrn3p and core factor (CF). Pol I is required for stable association of CF with the promoter and can be recruited in the absence of Rrn3p. Upon transcription initiation, Pol I-Rrn3p and CF dissociate from the promoter while UAF remains behind. These findings support a novel model in which the Pol I basal machinery cycles on and off the promoter with each round of transcription. This model accounts for previous observations that rRNA synthesis may be controlled by regulating both promoter accessibility and polymerase activity.

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