scholarly journals Species-specific rDNA transcription is due to promoter-specific binding factors.

1984 ◽  
Vol 4 (2) ◽  
pp. 221-227 ◽  
Author(s):  
R Miesfeld ◽  
N Arnheim
Keyword(s):  
Rna Polymerase ◽  
Transcriptional Control ◽  
Specific Binding ◽  
Rna Polymerase I ◽  
Rdna Transcription ◽  
Nucleolar Dominance ◽  
Cell Extracts ◽  
Species Specific ◽  
Polymerase I

RNA polymerase I transcription factors were purified from HeLa and mouse L cell extracts by phosphocellulose chromatography. Three fractions from each species were found to be required for transcription. One of these fractions, virtually devoid of RNA polymerase I activity, was found to form a stable preinitiation complex with small DNA fragments containing promoter sequences from the homologous but not the heterologous species. These species-specific DNA-binding factors can explain nucleolar dominance in vivo in mouse-human hybrid somatic cells and species specificity in cell-free, RNA polymerase I-dependent transcription systems. The evolution of species-specific transcriptional control signals may be the natural outcome of a special relationship that exists between the RNA polymerase I transcription machinery and the multigene family coding for rRNA.

Species-specific rDNA transcription is due to promoter-specific binding factors

1984 ◽  
Vol 4 (2) ◽  
pp. 221-227
Author(s):  
R Miesfeld ◽  
N Arnheim
Keyword(s):  
Rna Polymerase ◽  
Transcriptional Control ◽  
Specific Binding ◽  
Rna Polymerase I ◽  
Rdna Transcription ◽  
Nucleolar Dominance ◽  
Cell Extracts ◽  
Species Specific ◽  
Polymerase I

RNA polymerase I transcription factors were purified from HeLa and mouse L cell extracts by phosphocellulose chromatography. Three fractions from each species were found to be required for transcription. One of these fractions, virtually devoid of RNA polymerase I activity, was found to form a stable preinitiation complex with small DNA fragments containing promoter sequences from the homologous but not the heterologous species. These species-specific DNA-binding factors can explain nucleolar dominance in vivo in mouse-human hybrid somatic cells and species specificity in cell-free, RNA polymerase I-dependent transcription systems. The evolution of species-specific transcriptional control signals may be the natural outcome of a special relationship that exists between the RNA polymerase I transcription machinery and the multigene family coding for rRNA.

The absence of a human-specific ribosomal DNA transcription factor leads to nucleolar dominance in mouse greater than human hybrid cells

1984 ◽  
Vol 4 (7) ◽  
pp. 1306-1312
Author(s):  
R Miesfeld ◽  
B Sollner-Webb ◽  
C Croce ◽  
N Arnheim
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Hybrid Cell ◽  
Rna Polymerase I ◽  
Hybrid Cells ◽  
Rdna Transcription ◽  
Nucleolar Dominance ◽  
Cell Extracts ◽  
Polymerase I ◽  
Human Specific

The basis for nucleolar dominance in mouse-human cell hybrids which contained all of the mouse chromosomes but an incomplete set of human chromosomes (M greater than H) was examined at the molecular level. S1 mapping data showed that these cells had the expected levels of steady-state rRNA transcribed from mouse ribosomal gene (rDNA) transcription units but undetectable levels of rRNA derived from the human rDNA transcription templates that are also present. RNA polymerase I-dependent, cell-free transcription extracts were made from three hybrid lines and were found to be capable of transcribing cloned rDNA templates of mouse but not human origin. Partially purified human factors required for rDNA transcription in vitro were added to the M greater than H extracts. One fraction with almost no RNA polymerase I activity conferred on these hybrid cell extracts the ability to transcribe a human rDNA template. These rescue experiments suggested that this required human-specific rDNA transcription factor(s) was effectively absent from the lines we examined and could account for nucleolar dominance in M greater than H hybrid cells.

scholarly journals The absence of a human-specific ribosomal DNA transcription factor leads to nucleolar dominance in mouse greater than human hybrid cells.

1984 ◽  
Vol 4 (7) ◽  
pp. 1306-1312 ◽  
Author(s):  
R Miesfeld ◽  
B Sollner-Webb ◽  
C Croce ◽  
N Arnheim
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Hybrid Cell ◽  
Rna Polymerase I ◽  
Hybrid Cells ◽  
Rdna Transcription ◽  
Nucleolar Dominance ◽  
Cell Extracts ◽  
Polymerase I ◽  
Human Specific

The basis for nucleolar dominance in mouse-human cell hybrids which contained all of the mouse chromosomes but an incomplete set of human chromosomes (M greater than H) was examined at the molecular level. S1 mapping data showed that these cells had the expected levels of steady-state rRNA transcribed from mouse ribosomal gene (rDNA) transcription units but undetectable levels of rRNA derived from the human rDNA transcription templates that are also present. RNA polymerase I-dependent, cell-free transcription extracts were made from three hybrid lines and were found to be capable of transcribing cloned rDNA templates of mouse but not human origin. Partially purified human factors required for rDNA transcription in vitro were added to the M greater than H extracts. One fraction with almost no RNA polymerase I activity conferred on these hybrid cell extracts the ability to transcribe a human rDNA template. These rescue experiments suggested that this required human-specific rDNA transcription factor(s) was effectively absent from the lines we examined and could account for nucleolar dominance in M greater than H hybrid cells.

scholarly journals Polymerase III transcription factor B activity is reduced in extracts of growth-restricted cells.

1988 ◽  
Vol 8 (2) ◽  
pp. 1001-1005 ◽  
Author(s):  
J Tower ◽  
B Sollner-Webb
Keyword(s):  
Rna Polymerase ◽  
Stationary Phase ◽  
Rna Polymerase Iii ◽  
Control Cell ◽  
Rna Polymerase I ◽  
Rdna Transcription ◽  
Down Regulation ◽  
Cell Extracts ◽  
Polymerase Iii ◽  
Polymerase I

Extracts of cells that are down-regulated for transcription by RNA polymerase I and RNA polymerase III exhibit a reduced in vitro transcriptional capacity. We have recently demonstrated that the down-regulation of polymerase I transcription in extracts of cycloheximide-treated and stationary-phase cells results from a lack of an activated subform of RNA polymerase I which is essential for rDNA transcription. To examine whether polymerase III transcriptional down-regulation occurs by a similar mechanism, the polymerase III transcription factors were isolated and added singly and in pairs to control cell extracts and to extracts of cells that had reduced polymerase III transcriptional activity due to cycloheximide treatment or growth into stationary phase. These down-regulations result from a specific reduction in TFIIIB; TFIIIC and polymerase III activities remain relatively constant. Thus, although transcription by both polymerase III and polymerase I is substantially decreased in extracts of growth-arrested cells, this regulation is brought about by reduction of different kinds of activities: a component of the polymerase III stable transcription complex in the former case and the activated subform of RNA polymerase I in the latter.

scholarly journals The dynamic assembly of distinct RNA polymerase I complexes modulates rDNA transcription

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Eva Torreira ◽  
Jaime Alegrio Louro ◽  
Irene Pazos ◽  
Noelia González-Polo ◽  
David Gil-Carton ◽  
...  
Keyword(s):  
Cell Growth ◽  
Rna Polymerase ◽  
Ribosome Biogenesis ◽  
Mutational Analysis ◽  
Rna Polymerase I ◽  
Initiation Factor ◽  
Rdna Transcription ◽  
Pol I ◽  
Polymerase I

Cell growth requires synthesis of ribosomal RNA by RNA polymerase I (Pol I). Binding of initiation factor Rrn3 activates Pol I, fostering recruitment to ribosomal DNA promoters. This fundamental process must be precisely regulated to satisfy cell needs at any time. We present in vivo evidence that, when growth is arrested by nutrient deprivation, cells induce rapid clearance of Pol I–Rrn3 complexes, followed by the assembly of inactive Pol I homodimers. This dual repressive mechanism reverts upon nutrient addition, thus restoring cell growth. Moreover, Pol I dimers also form after inhibition of either ribosome biogenesis or protein synthesis. Our mutational analysis, based on the electron cryomicroscopy structures of monomeric Pol I alone and in complex with Rrn3, underscores the central role of subunits A43 and A14 in the regulation of differential Pol I complexes assembly and subsequent promoter association.

scholarly journals Recruitment of the Nucleolar Remodeling Complex NoRC Establishes Ribosomal DNA Silencing in Chromatin

2004 ◽  
Vol 24 (4) ◽  
pp. 1791-1798 ◽  
Author(s):  
Ralf Strohner ◽  
Attila Németh ◽  
Karl P. Nightingale ◽  
Ingrid Grummt ◽  
Peter B. Becker ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Ribosomal Dna ◽  
Active Role ◽  
Rna Polymerase I ◽  
In Vivo Studies ◽  
Rrna Gene ◽  
Rdna Transcription ◽  
Transcription Terminator ◽  
Polymerase I

ABSTRACT The rRNA gene cluster consists of multiple transcription units. Half of these are active, while the other half are transcriptionally inactive. Previously, in vivo studies have demonstrated that silencing of ribosomal DNA (rDNA) is mediated by the chromatin remodeling NoRC (nucleolar remodeling complex). To explore the mechanisms underlying NoRC-directed silencing of rDNA transcription, we investigated the effect of recombinant NoRC on RNA polymerase I transcription on reconstituted chromatin templates. We show that NoRC interacts with the transcription terminator factor (TTF-I), and this interaction is required both for the binding of TTF-I to its promoter-proximal target site and for the recruitment of NoRC to the promoter. After association with the rDNA promoter, NoRC alters the position of the promoter-bound nucleosome, thereby repressing RNA polymerase I transcription. This NoRC-directed rDNA repression requires the N terminus of histone H4. Repression is effective before preinitiation complex formation and as such is unable to exert an effect upon activated rDNA genes. Furthermore, the early steps of rDNA repression do not depend on DNA and histone modifications. These results reveal an important role for TTF-I in recruiting NoRC to rDNA and an active role for NoRC in the establishment of rDNA silencing.

Polymerase III transcription factor B activity is reduced in extracts of growth-restricted cells

1988 ◽  
Vol 8 (2) ◽  
pp. 1001-1005 ◽  
Author(s):  
J Tower ◽  
B Sollner-Webb
Keyword(s):  
Rna Polymerase ◽  
Stationary Phase ◽  
Rna Polymerase Iii ◽  
Control Cell ◽  
Rna Polymerase I ◽  
Rdna Transcription ◽  
Down Regulation ◽  
Cell Extracts ◽  
Polymerase Iii ◽  
Polymerase I

Extracts of cells that are down-regulated for transcription by RNA polymerase I and RNA polymerase III exhibit a reduced in vitro transcriptional capacity. We have recently demonstrated that the down-regulation of polymerase I transcription in extracts of cycloheximide-treated and stationary-phase cells results from a lack of an activated subform of RNA polymerase I which is essential for rDNA transcription. To examine whether polymerase III transcriptional down-regulation occurs by a similar mechanism, the polymerase III transcription factors were isolated and added singly and in pairs to control cell extracts and to extracts of cells that had reduced polymerase III transcriptional activity due to cycloheximide treatment or growth into stationary phase. These down-regulations result from a specific reduction in TFIIIB; TFIIIC and polymerase III activities remain relatively constant. Thus, although transcription by both polymerase III and polymerase I is substantially decreased in extracts of growth-arrested cells, this regulation is brought about by reduction of different kinds of activities: a component of the polymerase III stable transcription complex in the former case and the activated subform of RNA polymerase I in the latter.

scholarly journals Factor C*, the specific initiation component of the mouse RNA polymerase I holoenzyme, is inactivated early in the transcription process.

1994 ◽  
Vol 14 (7) ◽  
pp. 5010-5021 ◽  
Author(s):  
R P Brun ◽  
K Ryan ◽  
B Sollner-Webb
Keyword(s):  
Rna Polymerase ◽  
Critical Distance ◽  
Rna Polymerase I ◽  
Rrna Gene ◽  
Rdna Transcription ◽  
Transcription Process ◽  
Factor C ◽  
Polymerase I

Factor C* is the component of the RNA polymerase I holoenzyme (factor C) that allows specific transcriptional initiation on a factor D (SL1)- and UBF-activated rRNA gene promoter. The in vitro transcriptional capacity of a preincubated rDNA promoter complex becomes exhausted very rapidly upon initiation of transcription. This is due to the rapid depletion of C* activity. In contrast, C* activity is not unstable in the absence of transcription, even in the presence of nucleoside triphosphates (NTPs). By using 3'dNTPs to specifically halt elongation, C* is seen to remain active through transcription complex assembly, initiation, and the first approximately 37 nucleotides of elongation, but it is inactivated before synthesis proceeds beyond approximately 40 nucleotides. When elongation is halted before this critical distance, the C* remains active and on that template complex, greatly extending the kinetics of transcription and generating manyfold more transcripts than would have been synthesized if elongation had proceeded past the critical distance where C* is inactivated. In complementary in vivo analysis under conditions where C* activity is not replenished, C* activity becomes depleted from cells, but this also occurs only when there is ongoing rDNA transcription. Thus, both in vitro and in vivo, the specific initiation-conferring component of the RNA polymerase I holoenzyme is used stoichiometrically in the transcription process.

Factor C*, the specific initiation component of the mouse RNA polymerase I holoenzyme, is inactivated early in the transcription process

1994 ◽  
Vol 14 (7) ◽  
pp. 5010-5021
Author(s):  
R P Brun ◽  
K Ryan ◽  
B Sollner-Webb
Keyword(s):  
Rna Polymerase ◽  
Critical Distance ◽  
Rna Polymerase I ◽  
Rrna Gene ◽  
Rdna Transcription ◽  
Transcription Process ◽  
Factor C ◽  
Polymerase I

Factor C* is the component of the RNA polymerase I holoenzyme (factor C) that allows specific transcriptional initiation on a factor D (SL1)- and UBF-activated rRNA gene promoter. The in vitro transcriptional capacity of a preincubated rDNA promoter complex becomes exhausted very rapidly upon initiation of transcription. This is due to the rapid depletion of C* activity. In contrast, C* activity is not unstable in the absence of transcription, even in the presence of nucleoside triphosphates (NTPs). By using 3'dNTPs to specifically halt elongation, C* is seen to remain active through transcription complex assembly, initiation, and the first approximately 37 nucleotides of elongation, but it is inactivated before synthesis proceeds beyond approximately 40 nucleotides. When elongation is halted before this critical distance, the C* remains active and on that template complex, greatly extending the kinetics of transcription and generating manyfold more transcripts than would have been synthesized if elongation had proceeded past the critical distance where C* is inactivated. In complementary in vivo analysis under conditions where C* activity is not replenished, C* activity becomes depleted from cells, but this also occurs only when there is ongoing rDNA transcription. Thus, both in vitro and in vivo, the specific initiation-conferring component of the RNA polymerase I holoenzyme is used stoichiometrically in the transcription process.

Sign in / Sign up

Export Citation Format

Share Document