scholarly journals Early effects of oestradiol-17β on the chromatin and activity of the deoxyribonucleic acid-dependent ribonucleic acid polymerases (I and II) of the rat uterus

1972 ◽  
Vol 130 (4) ◽  
pp. 947-957 ◽  
Author(s):  
S. R. Glasser ◽  
F. Chytil ◽  
T. C. Spelsberg
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Synthesis ◽  
Ovariectomized Rats ◽  
Rrna Synthesis ◽  
Exact Nature ◽  
Control Activity ◽  
Chromatin Proteins ◽  
Early Effects ◽  
Polymerase I

Oestradiol-17β (1.0μg) was injected intravenously into ovariectomized rats. The earliest detectable hormonal response in isolated uterine nuclei was an increase (10–15min) in RNA polymerase II activity (DNA-like RNA synthesis), which reached a peak at 30min and then decreased to control values (by 1–2h) before displaying a second increase over control activity from 2 to 12h. The next response to oestradiol-17β was an increase (30–60min) in polymerase I activity (rRNA synthesis) and template capacity of the chromatin. The concentrations of acidic chromatin proteins did not begin to increase until 1h after injection of oestradiol-17β and histone concentrations showed no significant changes during the 8h period after administration. The early (15min) increase in RNA synthesis in `high-salt conditions' can be completely eliminated by α-amanitin, an inhibitor of the RNA polymerase II. The exact nature of this early increase in endogenous polymerase II activity remains to be determined, e.g. whether it is caused by the increased availability of transcribable DNA of the chromatin or via direct hormonal activation of the enzyme per se.

scholarly journals Conditional expression of RPA190, the gene encoding the largest subunit of yeast RNA polymerase I: effects of decreased rRNA synthesis on ribosomal protein synthesis.

1990 ◽  
Vol 10 (5) ◽  
pp. 2049-2059 ◽  
Author(s):  
M Wittekind ◽  
J M Kolb ◽  
J Dodd ◽  
M Yamagishi ◽  
S Mémet ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Rna Polymerase I ◽  
Northern Analysis ◽  
Rrna Synthesis ◽  
Synthesis Rate ◽  
Conditional Expression ◽  
Regulation Model ◽  
Polymerase I ◽  
Precursor Mrna

The synthesis of ribosomal proteins (r proteins) under the conditions of greatly reduced RNA synthesis were studied by using a strain of the yeast Saccharomyces cerevisiae in which the production of the largest subunit (RPA190) of RNA polymerase I was controlled by the galactose promoter. Although growth on galactose medium was normal, the strain was unable to sustain growth when shifted to glucose medium. This growth defect was shown to be due to a preferential decrease in RNA synthesis caused by deprivation of RNA polymerase I. Under these conditions, the accumulation of r proteins decreased to match the rRNA synthesis rate. When proteins were pulse-labeled for short periods, no or only a weak decrease was observed in the differential synthesis rate of several r proteins (L5, L39, L29 and/or L28, L27 and/or S21) relative to those of control cells synthesizing RPA190 from the normal promoter. Degradation of these r proteins synthesized in excess was observed during subsequent chase periods. Analysis of the amounts of mRNAs for L3 and L29 and their locations in polysomes also suggested that the synthesis of these proteins relative to other cellular proteins were comparable to those observed in control cells. However, Northern analysis of several r-protein mRNAs revealed that the unspliced precursor mRNA for r-protein L32 accumulated when rRNA synthesis rates were decreased. This result supports the feedback regulation model in which excess L32 protein inhibits the splicing of its own precursor mRNA, as proposed by previous workers (M. D. Dabeva, M. A. Post-Beittenmiller, and J. R. Warner, Proc. Natl. Acad. Sci. USA 83:5854-5857, 1986).

Cytoplasmic to nuclear translocation of RNA polymerase I is required for lipopolysaccharide-induced nucleolar RNA synthesis and subsequent DNA synthesis in murine B lymphocytes

1989 ◽  
Vol 92 (1) ◽  
pp. 101-109
Author(s):  
M.S. Halleck ◽  
R.A. Schlegel ◽  
K.M. Rose
Keyword(s):  
Rna Polymerase ◽  
Dna Synthesis ◽  
B Lymphocytes ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Nuclear Translocation ◽  
Rna Polymerase I ◽  
Nuclear Accumulation ◽  
Rrna Synthesis ◽  
Polymerase I

The synthesis of ribosomal RNA (rRNA) in murine B lymphocytes is markedly elevated in response to mitogens such as lipopolysaccharide (LPS). First, to investigate the mechanism involved, antibodies directed against RNA polymerase I, the enzyme responsible for transcription of ribosomal genes, were introduced into the cytoplasm of lymphocytes via red cell-mediated microinjection and the ability of cells to synthesize RNA was examined. Simultaneous immunofluorescence/autoradiography revealed that 7% or less of the cells injected with specific antibodies prior to stimulation were actively synthesizing rRNA 15 or 40 h following LPS addition. In contrast 19% and 27% of cells injected with control IgG were active at these times. Non-ribosomal RNA synthesis was unaffected by the presence of anti-RNA polymerase I antibodies. Since antibodies injected into the cytoplasm were limited to that compartment, these data suggest that rRNA synthesis induced by LPS requires translocation of cytoplasmic RNA polymerase I into the nucleus. Second, to test whether synthesis of rRNA is required for entry into S phase, the effect of anti-RNA polymerase I antibodies on DNA synthesis in response to LPS was evaluated. Only 7% of cells containing anti-RNA polymerase I antibodies had initiated DNA synthesis 40 h after LPS addition whereas 25% of cells containing control IgG were actively synthesizing DNA at that time. These results suggest that nuclear accumulation of RNA polymerase I and increased rRNA synthesis are required for LPS-induced DNA synthesis in B lymphocytes.

scholarly journals HSF1 induces RNA polymerase II synthesis of ribosomal RNA in S. cerevisiae during nitrogen deprivation

2021 ◽  
Author(s):  
Arjuna Rao Vallabhaneni ◽  
Merita Kabashi ◽  
Matt Haymowicz ◽  
Kushal Bhatt ◽  
Violet Wayman ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Underlying Mechanism ◽  
Rrna Synthesis ◽  
Nitrogen Deprivation ◽  
Environmental Stress Response ◽  
Pol Ii ◽  
Ribosome Synthesis ◽  
Pol I ◽  
Polymerase I

AbstractThe resource intensive process of accurate ribosome synthesis is essential for cell viability in all organisms. Ribosome synthesis regulation centers on RNA polymerase I (pol I) transcription of a 35S rRNA precursor that is processed into the mature 18S, 5.8S and 25S rRNAs. During nutrient deprivation or stress, pol I synthesis of rRNA is dramatically reduced. Conversely, chronic stress such as mitochondrial dysfunction induces RNA polymerase II (pol II) to transcribe functional rRNA using an evolutionarily conserved cryptic pol II rDNA promoter suggesting a universal phenomenon. However, this polymerase switches and its role in regulation of rRNA synthesis remain unclear. In this paper, we demonstrate that extended nitrogen deprivation induces the polymerase switch via components of the environmental stress response. We further show that the switch is repressed by Sch9 and activated by the stress kinase Rim15. Like stress-induced genes, the switch requires not only pol II transcription machinery, including the mediator, but also requires the HDAC, Rpd3 and stress transcription factor Hsf1. The current work shows that the constitutive allele, Hsf1PO4* displays elevated levels of induction in non-stress conditions while binding to a conserved site in the pol II rDNA promoter upstream of the pol I promoter. Whether the polymerase switch serves to provide rRNA when pol I transcription is inhibited or fine-tunes pol I initiation via RNA interactions is yet to be determined. Identifying the underlying mechanism for this evolutionary conserved phenomenon will help understand the mechanism of pol II rRNA synthesis and its role in stress adaptation.

A Drosophila anti-RNA polymerase II antibody recognizes a plant nucleolar antigen, RNA polymerase I, which is mostly localized in fibrillar centres

1991 ◽  
Vol 100 (1) ◽  
pp. 99-107 ◽  
Author(s):  
M. Martin ◽  
F.J. Medina
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Large Subunit ◽  
Rna Polymerases ◽  
Rna Polymerase I ◽  
Rrna Synthesis ◽  
Dense Fibrillar Component ◽  
Transition Area ◽  
Fibrillar Component ◽  
Polymerase I

The distribution of nucleolar RNA polymerase in the nucleolus of onion root meristematic cells has been studied by means of an antibody originally raised against Drosophila RNA polymerase II. This antibody recognizes the homologous domains of the large subunit of the enzyme, which are highly conserved throughout evolution in the three classes of eucaryotic RNA polymerases. Given that RNA polymerase I is confined to the nucleolus, and that the onion cell nucleolus lacks digitations of extranucleolar chromatin, we conclude that the nucleolar enzyme localized is RNA polymerase I. A quantitative approach, independent of the existence of borderlines between nucleolar fibrillar centres and the dense fibrillar component, allowed us to show that the enzyme is localized in fibrillar centres and in the transition area between them and the dense fibrillar component, in parallel with the nucleolar DNA. These results, together with previous autoradiographic, cytochemical and immunocytochemical results, in this and other species, lead us to conclude that the activation of rDNA for transcription occurs in the fibrillar centres and pre-rRNA synthesis is expressed at the transition area between fibrillar centres and the dense fibrillar component. Fibrillar centres are connected to each other by extended RNA polymerase-bound DNA fibres, presumably active in transcription. This work provides evidence of the high evolutionary conservation of some domains of the large subunit of RNA polymerases and of the existence of fibrillar centres in the nucleolus of plant cells, totally homologous to those described in mammalian cells.

Functional states of RNA polymerase in the macronucleus of Tetrahymena pyriformis and their dependence on culture growth

1981 ◽  
Vol 47 (1) ◽  
pp. 267-275
Author(s):  
M. Freiburg
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Synthesis ◽  
Tetrahymena Pyriformis ◽  
Ribosomal Genes ◽  
Rna Polymerase I ◽  
Functional States ◽  
Culture Growth ◽  
The One ◽  
Polymerase I

RNA polymerase In in macronuclei of late log-phase cells of the ciliate Tetrahymena pyriformis is found to be present in 2 functional states, the one being actively engaged in transcription of ribosomal genes, the other one in a “free” state, i.e. free to transcribe added DNA or poly d(AT). Stimulation of RNA synthesis induced by dilution of stationary-phase cells into fresh medium is correlated with an increase in activity of template engaged and a decrease of free RNA polymerase I. In contrast, RNA polymerase II shows no pronounced changes in activity and is not available to transcribe poly d(AT). The data favour the assumption that factors other than the amount of RNA polymerase I molecules available control transcription of the ribosomal genes.

Conditional expression of RPA190, the gene encoding the largest subunit of yeast RNA polymerase I: effects of decreased rRNA synthesis on ribosomal protein synthesis

1990 ◽  
Vol 10 (5) ◽  
pp. 2049-2059
Author(s):  
M Wittekind ◽  
J M Kolb ◽  
J Dodd ◽  
M Yamagishi ◽  
S Mémet ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Rna Polymerase I ◽  
Northern Analysis ◽  
Rrna Synthesis ◽  
Synthesis Rate ◽  
Conditional Expression ◽  
Regulation Model ◽  
Polymerase I ◽  
Precursor Mrna

The synthesis of ribosomal proteins (r proteins) under the conditions of greatly reduced RNA synthesis were studied by using a strain of the yeast Saccharomyces cerevisiae in which the production of the largest subunit (RPA190) of RNA polymerase I was controlled by the galactose promoter. Although growth on galactose medium was normal, the strain was unable to sustain growth when shifted to glucose medium. This growth defect was shown to be due to a preferential decrease in RNA synthesis caused by deprivation of RNA polymerase I. Under these conditions, the accumulation of r proteins decreased to match the rRNA synthesis rate. When proteins were pulse-labeled for short periods, no or only a weak decrease was observed in the differential synthesis rate of several r proteins (L5, L39, L29 and/or L28, L27 and/or S21) relative to those of control cells synthesizing RPA190 from the normal promoter. Degradation of these r proteins synthesized in excess was observed during subsequent chase periods. Analysis of the amounts of mRNAs for L3 and L29 and their locations in polysomes also suggested that the synthesis of these proteins relative to other cellular proteins were comparable to those observed in control cells. However, Northern analysis of several r-protein mRNAs revealed that the unspliced precursor mRNA for r-protein L32 accumulated when rRNA synthesis rates were decreased. This result supports the feedback regulation model in which excess L32 protein inhibits the splicing of its own precursor mRNA, as proposed by previous workers (M. D. Dabeva, M. A. Post-Beittenmiller, and J. R. Warner, Proc. Natl. Acad. Sci. USA 83:5854-5857, 1986).

Structural alterations of the nucleolus in mutants of Saccharomyces cerevisiae defective in RNA polymerase I

1993 ◽  
Vol 13 (4) ◽  
pp. 2441-2455
Author(s):  
M Oakes ◽  
Y Nogi ◽  
M W Clark ◽  
M Nomura
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Polymerase I ◽  
Rrna Synthesis ◽  
Rrna Processing ◽  
Structural Element ◽  
Nucleolar Structure ◽  
Pol I ◽  
Polymerase I

We have previously constructed mutants of Saccharomyces cerevisiae in which the gene for the second-largest subunit of RNA polymerase I (Pol I) is deleted. In these mutants, rRNA is synthesized by RNA polymerase II from a hybrid gene consisting of the 35S rRNA coding region fused to the GAL7 promoter on a plasmid. These strains thus grow in galactose but not glucose media. By immunofluorescence microscopy using antibodies against the known nucleolar proteins SSB1 and fibrillarin, we found that the intact crescent-shaped nucleolar structure is absent in these mutants; instead, several granules (called mininucleolar bodies [MNBs]) that stained with these antibodies were seen in the nucleus. Conversion of the intact nucleolar structure to MNBs was also observed in Pol I temperature-sensitive mutants at nonpermissive temperatures. These MNBs may structurally resemble prenucleolar bodies observed in higher eukaryotic cells and may represent a constituent of the normal nucleolus. Furthermore, cells under certain conditions that inhibit rRNA synthesis did not cause conversion of the nucleolus to MNBs. Thus, the role of Pol I in the maintenance of the intact nucleolar structure might include a role as a structural element in addition to (or instead of) a functional role to produce rRNA transcripts. Our study also shows that the intact nucleolar structure is not absolutely required for rRNA processing, ribosome assembly, or cell growth and that MNBs are possibly functional in rRNA processing in the Pol I deletion mutants.

scholarly journals Structural alterations of the nucleolus in mutants of Saccharomyces cerevisiae defective in RNA polymerase I.

1993 ◽  
Vol 13 (4) ◽  
pp. 2441-2455 ◽  
Author(s):  
M Oakes ◽  
Y Nogi ◽  
M W Clark ◽  
M Nomura
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Polymerase I ◽  
Rrna Synthesis ◽  
Rrna Processing ◽  
Structural Element ◽  
Nucleolar Structure ◽  
Pol I ◽  
Polymerase I

We have previously constructed mutants of Saccharomyces cerevisiae in which the gene for the second-largest subunit of RNA polymerase I (Pol I) is deleted. In these mutants, rRNA is synthesized by RNA polymerase II from a hybrid gene consisting of the 35S rRNA coding region fused to the GAL7 promoter on a plasmid. These strains thus grow in galactose but not glucose media. By immunofluorescence microscopy using antibodies against the known nucleolar proteins SSB1 and fibrillarin, we found that the intact crescent-shaped nucleolar structure is absent in these mutants; instead, several granules (called mininucleolar bodies [MNBs]) that stained with these antibodies were seen in the nucleus. Conversion of the intact nucleolar structure to MNBs was also observed in Pol I temperature-sensitive mutants at nonpermissive temperatures. These MNBs may structurally resemble prenucleolar bodies observed in higher eukaryotic cells and may represent a constituent of the normal nucleolus. Furthermore, cells under certain conditions that inhibit rRNA synthesis did not cause conversion of the nucleolus to MNBs. Thus, the role of Pol I in the maintenance of the intact nucleolar structure might include a role as a structural element in addition to (or instead of) a functional role to produce rRNA transcripts. Our study also shows that the intact nucleolar structure is not absolutely required for rRNA processing, ribosome assembly, or cell growth and that MNBs are possibly functional in rRNA processing in the Pol I deletion mutants.

Control points in eucaryotic ribosome biogenesis

1991 ◽  
Vol 69 (1) ◽  
pp. 5-22 ◽  
Author(s):  
D. E. Larson ◽  
P. Zahradka ◽  
B. H. Sells
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Rna Polymerase Iii ◽  
Ribosomal Subunits ◽  
Rrna Species ◽  
Polymerase I ◽  
Ribosomal Precursor ◽  
Precursor Molecules

Ribosome biogenesis in eucaryotic cells involves the coordinated synthesis of four rRNA species, transcribed by RNA polymerase I (18S, 28S, 5.8S) and RNA polymerase III (5S), and approximately 80 ribosomal proteins translated from mRNAs synthesized by RNA polymerase II. Assembly of the ribosomal subunits in the nucleolus, the site of 45S rRNA precursor gene transcription, requires the movement of 5S rRNA and ribosomal proteins from the nucleoplasm and cytoplasm, respectively, to this structure. To integrate these events and ensure the balanced production of individual ribosomal components, different strategies have been developed by eucaryotic organisms in response to a variety of physiological changes. This review presents an overview of the mechanisms modulating the production of ribosomal precursor molecules and the rate of ribosome biogenesis in various biological systems.Key words: rRNA, ribosomal proteins, nucleolus, ribosome.

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