scholarly journals RNA synthesis in regenerating mouse liver evaluated by incorporation of [methyl-14C]methionine and by determination of RNA polymerase activity

1984 ◽  
Vol 221 (1) ◽  
pp. 235-239 ◽  
Author(s):  
I Ljungquist ◽  
T Yngner ◽  
L Lewan ◽  
C Engelbrecht
Keyword(s):  
Rna Polymerase ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Mouse Liver ◽  
Specific Radioactivity ◽  
Total Activity ◽  
Polymerase Activity ◽  
Rna Polymerase Activity ◽  
The Difference ◽  
Polymerase I

The synthesis of RNA during mouse liver regeneration was studied by two different methods at 24 and 48 h after partial hepatectomy. Total chromatin-bound RNA polymerase activity showed an increase of 32% at 24 h after partial hepatectomy. At 48 h a slight increase in total activity was also observed in regenerating liver, but the difference was not significant. The increase in total RNA polymerase activity was due to a rise in RNA polymerase I plus III activity. This enzyme activity was increased at both 24 and 48 h. The increase was 57% at 24 h and 51% at 48 h. When [methyl-14C]methionine was used for labelling of methyl groups in rRNA, there was an increased specific radioactivity of this class of RNA at both 24 h and 48 h. The increases were 263 and 103% at 24 and 48 h respectively. Thus both methods revealed an increased synthesis of rRNA during mouse liver regeneration. The results are discussed in relation to previous results from this laboratory [Yngner, Carlberg, Lewan & Engelbrecht (1979) Hoppe-Seyler's Z. Physiol. Chem. 360, 1069-1074; Yngner, Engelbrecht, Lewan & Annerfeldt (1979) Biochem. J. 178, 1-8; Yngner, Bengtsson, Carlberg, Engelbrecht & Wieslander (1980) Exp. Cell. Biol. 48, 393-403], which have shown that the incorporation of orotic acid or uridine into RNA is not increased in mouse liver regenerating after partial hepatectomy.

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.

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.

Pharmaceutical interference of the EWS-FLI1-driven transcriptome by co-targeting H3K27ac and RNA polymerase activity in Ewing Sarcoma

2021 ◽  
pp. molcanther.MCT-20-0489-A.2020
Author(s):  
Daniel A. R. Heisey ◽  
Sheeba Jacob ◽  
Timonthy L Lochmann ◽  
Richard Kurupi ◽  
Maninderjit S. Ghotra ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Ewing Sarcoma ◽  
Polymerase Activity ◽  
Rna Polymerase Activity

RNA polymerase activity in virions from Ustilago maydis

1984 ◽  
Vol 4 (1) ◽  
pp. 188-194
Author(s):  
B S Ben-Tzvi ◽  
Y Koltin ◽  
M Mevarech ◽  
A Tamarkin
Keyword(s):  
Rna Polymerase ◽  
Viral Genome ◽  
Ustilago Maydis ◽  
Polymerase Activity ◽  
Reaction Products ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Rna Transcripts ◽  
Rna Polymerase Activity

RNA polymerase activity is associated with the double-stranded RNA virions of Ustilago maydis. The reaction products of the polymerase activity are single-stranded RNA molecules. The RNA molecules synthesized are homologous to the three classes of double-stranded RNA molecules that typify the viral genome. The single-stranded RNA synthesized is released from the virions. The molecular weight of the single-stranded RNA transcripts is about half the size of the double-stranded RNA segments, and thus, it appears that in the in vitro reaction, full-length transcripts can be obtained.

scholarly journals HDAC6 Restricts Influenza A Virus by Deacetylation of the RNA Polymerase PA Subunit

2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Huan Chen ◽  
Yingjuan Qian ◽  
Xin Chen ◽  
Zhiyang Ruan ◽  
Yuetian Ye ◽  
...  
Keyword(s):  
Life Cycle ◽  
Rna Polymerase ◽  
Influenza A Virus ◽  
Influenza A ◽  
Molecular Mechanisms ◽  
Polymerase Activity ◽  
Negative Regulator ◽  
Host Protein ◽  
Spectrometric Analysis ◽  
Rna Polymerase Activity

ABSTRACT The life cycle of influenza A virus (IAV) is modulated by various cellular host factors. Although previous studies indicated that IAV infection is controlled by HDAC6, the deacetylase involved in the regulation of PA remained unknown. Here, we demonstrate that HDAC6 acts as a negative regulator of IAV infection by destabilizing PA. HDAC6 binds to and deacetylates PA, thereby promoting the proteasomal degradation of PA. Based on mass spectrometric analysis, Lys(664) of PA can be deacetylated by HDAC6, and the residue is crucial for PA protein stability. The deacetylase activity of HDAC6 is required for anti-IAV activity, because IAV infection was enhanced due to elevated IAV RNA polymerase activity upon HDAC6 depletion and an HDAC6 deacetylase dead mutant (HDAC6-DM; H216A, H611A). Finally, we also demonstrate that overexpression of HDAC6 suppresses IAV RNA polymerase activity, but HDAC6-DM does not. Taken together, our findings provide initial evidence that HDAC6 plays a negative role in IAV RNA polymerase activity by deacetylating PA and thus restricts IAV RNA transcription and replication. IMPORTANCE Influenza A virus (IAV) continues to threaten global public health due to drug resistance and the emergence of frequently mutated strains. Thus, it is critical to find new strategies to control IAV infection. Here, we discover one host protein, HDAC6, that can inhibit viral RNA polymerase activity by deacetylating PA and thus suppresses virus RNA replication and transcription. Previously, it was reported that IAV can utilize the HDAC6-dependent aggresome formation mechanism to promote virus uncoating, but HDAC6-mediated deacetylation of α-tubulin inhibits viral protein trafficking at late stages of the virus life cycle. These findings together will contribute to a better understanding of the role of HDAC6 in regulating IAV infection. Understanding the molecular mechanisms of HDAC6 at various periods of viral infection may illuminate novel strategies for developing antiviral drugs.

RNA polymerase activity in germinating onion seeds

1972 ◽  
Vol 11 (11) ◽  
pp. 3105-3110 ◽  
Author(s):  
J.F. Payne ◽  
Arya K. Bal
Keyword(s):  
Rna Polymerase ◽  
Polymerase Activity ◽  
Rna Polymerase Activity
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