CONTROL OF RNA SYNTHESIS IN YEAST

1974 ◽  
Vol 16 (4) ◽  
pp. 751-764
Author(s):  
H. O. Halvorson ◽  
D. Kaback ◽  
S. Sogin ◽  
E. M. Sajdel-Sulkowska ◽  
I. Takano
Keyword(s):  
Cell Cycle ◽  
Rna Synthesis ◽  
Rrna Synthesis ◽  
Mrna Synthesis ◽  
Continuous Increase ◽  
Level Of Activity ◽  
Physiological Properties ◽  
Polymerase I ◽  
Chromosome I ◽  
Definite Period

During the cell cycle in Saccharomyces cerevisiae there is an ordered appearance of a number of enzymes and various physiological properties but a continuous increase in the rate of rRNA synthesis. A detailed study of rRNA synthesis has shown that there are reiterated genes for rRNA which are largely clustered on chromosome I and appear to be transcribed continuously during the cell cycle. However, the level of activity of polymerase I is proportional to the level of rRNA during the cell cycle and is correlated with the growth rate of the culture. In contrast, the level of polymerase II, thought to be involved in mRNA synthesis, increases during a definite period of the cell cycle characteristic of step enzymes in yeast. It would appear that the level of the activity of polymerase I is involved in the regulation of rRNA synthesis. Possible other mechanisms for the regulation of rRNA are discussed.

scholarly journals Che-1/AATF binds to RNA polymerase I machinery and sustains ribosomal RNA gene transcription

2020 ◽  
Vol 48 (11) ◽  
pp. 5891-5906 ◽  
Author(s):  
Cristina Sorino ◽  
Valeria Catena ◽  
Tiziana Bruno ◽  
Francesca De Nicola ◽  
Stefano Scalera ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Rna Polymerase ◽  
Ribosomal Rna ◽  
Ribosome Biogenesis ◽  
Cellular Proliferation ◽  
Rna Polymerase I ◽  
Rrna Synthesis ◽  
Rrna Gene ◽  
Response To Stress ◽  
Polymerase I

Abstract Originally identified as an RNA polymerase II interactor, Che-1/AATF (Che-1) has now been recognized as a multifunctional protein involved in cell-cycle regulation and cancer progression, as well as apoptosis inhibition and response to stress. This protein displays a peculiar nucleolar localization and it has recently been implicated in pre-rRNA processing and ribosome biogenesis. Here, we report the identification of a novel function of Che-1 in the regulation of ribosomal RNA (rRNA) synthesis, in both cancer and normal cells. We demonstrate that Che-1 interacts with RNA polymerase I and nucleolar upstream binding factor (UBF) and promotes RNA polymerase I-dependent transcription. Furthermore, this protein binds to the rRNA gene (rDNA) promoter and modulates its epigenetic state by contrasting the recruitment of HDAC1. Che-1 downregulation affects RNA polymerase I and UBF recruitment on rDNA and leads to reducing rDNA promoter activity and 47S pre-rRNA production. Interestingly, Che-1 depletion induces abnormal nucleolar morphology associated with re-distribution of nucleolar proteins. Finally, we show that upon DNA damage Che-1 re-localizes from rDNA to TP53 gene promoter to induce cell-cycle arrest. This previously uncharacterized function of Che-1 confirms the important role of this protein in the regulation of ribosome biogenesis, cellular proliferation and response to stress.

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).

Regulation of ribosomal RNA synthesis in Tetrahymena pyriformis

1978 ◽  
Vol 31 (1) ◽  
pp. 13-23
Author(s):  
J. Keiding ◽  
H.A. Andersen
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Tetrahymena Pyriformis ◽  
Rrna Synthesis ◽  
Constant Rate ◽  
Normal Increase ◽  
S Period ◽  
Dosis Effect

Ribosomal RNA is synthesized at constant rate during most of the cell cycle in heat-shock synchronized populations of Tetrahymena pyriformis. Early in each macronuclear S-period the rate of synthesis increases abruptly, concomitant with replication of the genes coding for ribosomal RNA. The increase is prevented by inhibitors of DNA replication, added prior to the S-period. Similarly, in cultures synchronized by starvation/refeeding, inhibition of DNA replication, at the time when the rDNA is replicated, will prevent the normal increase in rate of RNA synthesis which follows refeeding. We conclude that inhibition of rDNA replication interferes with the synthesis of rRNA, and we suggest that with respect to rRNA synthesis a gene dosis effect is operating in fast-growing Tetrahymena cells.

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 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.

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).

High-resolution autoradiographic localization of DNA-containing sites and RNA synthesis in developing nucleoli of human preimplantation embryos: a new concept of embryonic nucleologenesis

Development ◽  
1987 ◽  
Vol 101 (4) ◽  
pp. 777-791 ◽  
Author(s):  
J. Tesarik ◽  
V. Kopecny ◽  
M. Plachot ◽  
J. Mandelbaum
Keyword(s):  
Rna Synthesis ◽  
Preimplantation Embryos ◽  
Synthetic Activity ◽  
Rrna Synthesis ◽  
Nucleolar Organizer Regions ◽  
Careful Study ◽  
Matrix Elements ◽  
Electron Microscopic Autoradiography ◽  
General Validity ◽  
Granular Component

Human embryos from the 2-cell to the morula stage, obtained by in vitro fertilization, were incubated with [3H]thymidine or [3H]uridine so as to achieve labelling of all replicating nuclear DNA and the newly synthesized RNA, respectively. The label was localized in different structural components of developing nucleoli using electron microscopic autoradiography. Careful study of the relationship between the structural pattern and nucleic acid distribution made it possible to define four stages of embryonic nucleologenesis. Homogeneous nuclear precursors (i) consist of nucleolar matrix elements appearing as filaments of 3 nm thickness, (ii) do not contain recently replicated DNA and (iii) lack RNA synthetic activity. Penetration of DNA into these bodies is a key event leading to their transformation into heterogeneous nucleolar precursors. In addition to the 3 nm matrix filaments, two types of 5 nm fibrillar components can be recognized in them. The denser type contains DNA and is the site of nucleolar RNA synthesis, while the more loosely arranged 5 nm fibrils are not labelled with [3H]thymidine and apparently represent the newly produced pre-rRNA detached from the transcribing rDNA filament. Compact fibrillogranular nucleoli are characterized by the first appearance of the granular component and reduction of the nontranscribing part of the fibrillar component, both indicating the activation of the machinery for rRNA processing. Finally, the granular component is most evident in reticulated nucleoli, occupying mostly the inner parts of their nucleolonema, while the transcription sites tend to be located at the nucleolar periphery. Our findings advocate a unique concept of embryonic nucleologenesis, different from any other nucleolar event during the cell cycle of differentiated cells. This developmental pattern is characterized by a gradual activation of rRNA synthesis and processing, mediated by progressive association of rDNA and, later on, the newly formed pre-rRNA with pre-existing nucleolar matrix elements that are originally topically separated from nucleolar organizer regions. This model may have a general validity in early animal embryos despite some interspecies variability in the timing of individual steps and resulting structural peculiarities.

Transcription of spacer sequences flanking the rat 45S ribosomal DNA gene

1987 ◽  
Vol 7 (1) ◽  
pp. 314-325
Author(s):  
C A Harrington ◽  
D M Chikaraishi
Keyword(s):  
Ribosomal Dna ◽  
Transcriptional Activity ◽  
Tandem Repeats ◽  
Initiation Site ◽  
Rrna Synthesis ◽  
Rna Transcripts ◽  
Pair Sequence ◽  
Polymerase I

The transcriptional activity of spacer sequences flanking the rat 45S ribosomal DNA (rDNA) gene were studied. Nascent RNA labeled in in vitro nuclear run-on reactions hybridized with both 5' and 3' spacer regions. The highest level of hybridization was seen with an rDNA fragment containing tandem repeats of a 130-base-pair sequence upstream of the 45S rRNA initiation site. Synthesis of RNA transcripts homologous to this internally repetitious spacer region was insensitive to high levels of alpha-amanitin, suggesting that it is mediated by RNA polymerase I. Analysis of steady-state RNA showed that these transcripts were present at extremely low levels in vivo relative to precursor rRNA transcripts. In contrast, precursor and spacer run-on RNAs were synthesized at similar levels. This suggests that spacer transcripts are highly unstable in vivo; therefore, it may be the process of transcription rather than the presence of spacer transcripts that is functionally important. Transcription in this upstream rDNA region may be involved in regulation of 45S rRNA synthesis in rodents, as has been suggested previously for frog rRNA. In addition, the presence of transcriptional activity in other regions of the spacer suggests that some polymerase I molecules may transcribe through the spacer from one 45S gene to the next on rodent rDNA.

scholarly journals Selective inhibition by zinc of RNA synthesis initiation in the RNA polymerase I reaction

FEBS Letters ◽  
1979 ◽  
Vol 99 (1) ◽  
pp. 29-32 ◽  
Author(s):  
Yoshikuni Nagamine ◽  
Den'ichi Mizuno ◽  
Shunji Natori
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Selective Inhibition ◽  
Rna Polymerase I ◽  
Polymerase I
Sign in / Sign up

Export Citation Format

Share Document