scholarly journals Rethinking the role of TFIIF in transcript initiation by RNA polymerase II

Transcription ◽  
2012 ◽  
Vol 3 (4) ◽  
pp. 156-159 ◽  
Author(s):  
Donal S. Luse
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcript Initiation

scholarly journals Loss of Ubp3 increases silencing, decreases unequal recombination in rDNA, and shortens the replicative life span in Saccharomyces cerevisiae

2014 ◽  
Vol 25 (12) ◽  
pp. 1916-1924 ◽  
Author(s):  
David Öling ◽  
Rehan Masoom ◽  
Kristian Kvint
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Life Span ◽  
Rna Polymerase Ii ◽  
Ribosomal Dna ◽  
Genetic Evidence ◽  
Wild Type ◽  
Replicative Life Span ◽  
Unequal Recombination

Ubp3 is a conserved ubiquitin protease that acts as an antisilencing factor in MAT and telomeric regions. Here we show that ubp3∆ mutants also display increased silencing in ribosomal DNA (rDNA). Consistent with this, RNA polymerase II occupancy is lower in cells lacking Ubp3 than in wild-type cells in all heterochromatic regions. Moreover, in a ubp3∆ mutant, unequal recombination in rDNA is highly suppressed. We present genetic evidence that this effect on rDNA recombination, but not silencing, is entirely dependent on the silencing factor Sir2. Further, ubp3∆ sir2∆ mutants age prematurely at the same rate as sir2∆ mutants. Thus our data suggest that recombination negatively influences replicative life span more so than silencing. However, in ubp3∆ mutants, recombination is not a prerequisite for aging, since cells lacking Ubp3 have a shorter life span than isogenic wild-type cells. We discuss the data in view of different models on how silencing and unequal recombination affect replicative life span and the role of Ubp3 in these processes.

scholarly journals Rpb7 Can Interact with RNA Polymerase II and Support Transcription during Some Stresses Independently of Rpb4

1999 ◽  
Vol 19 (4) ◽  
pp. 2672-2680 ◽  
Author(s):  
Ayelet Sheffer ◽  
Mazal Varon ◽  
Mordechai Choder
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Stress Conditions ◽  
Cold Sensitivity ◽  
Starvation Period ◽  
Wild Type ◽  
Pol Ii ◽  
Growth Phenotype ◽  
Mild Temperature

ABSTRACT Rpb4 and Rpb7 are two yeast RNA polymerase II (Pol II) subunits whose mechanistic roles have recently started to be deciphered. Although previous data suggest that Rpb7 can stably interact with Pol II only as a heterodimer with Rpb4, RPB7 is essential for viability, whereas RPB4 is essential only during some stress conditions. To resolve this discrepancy and to gain a better understanding of the mode of action of Rpb4, we took advantage of the inability of cells lacking RPB4 (rpb4Δ, containing Pol IIΔ4) to grow above 30°C and screened for genes whose overexpression could suppress this defect. We thus discovered that overexpression of RPB7 could suppress the inability ofrpb4Δ cells to grow at 34°C (a relatively mild temperature stress) but not at higher temperatures. Overexpression ofRPB7 could also partially suppress the cold sensitivity ofrpb4Δ strains and fully suppress their inability to survive a long starvation period (stationary phase). Notably, however, overexpression of RPB4 could not override the requirement for RPB7. Consistent with the growth phenotype, overexpression of RPB7 could suppress the transcriptional defect characteristic of rpb4Δ cells during the mild, but not during a more severe, heat shock. We also demonstrated, through two reciprocal coimmunoprecipitation experiments, a stable interaction of the overproduced Rpb7 with Pol IIΔ4. Nevertheless, fewer Rpb7 molecules interacted with Pol IIΔ4 than with wild-type Pol II. Thus, a major role of Rpb4 is to augment the interaction of Rpb7 with Pol II. We suggest that Pol IIΔ4 contains a small amount of Rpb7 that is sufficient to support transcription only under nonstress conditions. When RPB7 is overexpressed, more Rpb7 assembles with Pol IIΔ4, enough to permit appropriate transcription also under some stress conditions.

scholarly journals Novel critical role of a human Mediator complex for basal RNA polymerase II transcription

EMBO Reports ◽  
2001 ◽  
Vol 2 (9) ◽  
pp. 808-813 ◽  
Author(s):  
Gerhard Mittler ◽  
Elisabeth Kremmer ◽  
H Th. Marc Timmers ◽  
Michael Meisterernst
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Critical Role ◽  
Mediator Complex ◽  
Rna Polymerase Ii Transcription

scholarly journals RNA polymerase II plays an active role in the formation of gene loops through the Rpb4 subunit

2019 ◽  
Vol 47 (17) ◽  
pp. 8975-8987 ◽  
Author(s):  
Paula Allepuz-Fuster ◽  
Michael J O’Brien ◽  
Noelia González-Polo ◽  
Bianca Pereira ◽  
Zuzer Dhoondia ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Essential Role ◽  
Transcription Termination ◽  
Active Role ◽  
The Other ◽  
Loop Formation ◽  
Direct Role

AbstractGene loops are formed by the interaction of initiation and termination factors occupying the distal ends of a gene during transcription. RNAPII is believed to affect gene looping indirectly owing to its essential role in transcription. The results presented here, however, demonstrate a direct role of RNAPII in gene looping through the Rpb4 subunit. 3C analysis revealed that gene looping is abolished in the rpb4Δ mutant. In contrast to the other looping-defective mutants, rpb4Δ cells do not exhibit a transcription termination defect. RPB4 overexpression, however, rescued the transcription termination and gene looping defect of sua7-1, a mutant of TFIIB. Furthermore, RPB4 overexpression rescued the ssu72-2 gene looping defect, while SSU72 overexpression restored the formation of gene loops in rpb4Δ cells. Interestingly, the interaction of TFIIB with Ssu72 is compromised in rpb4Δ cells. These results suggest that the TFIIB–Ssu72 interaction, which is critical for gene loop formation, is facilitated by Rpb4. We propose that Rpb4 is promoting the transfer of RNAPII from the terminator to the promoter for reinitiation of transcription through TFIIB–Ssu72 mediated gene looping.

scholarly journals Human RNA cap1 methyltransferase CMTr1 cooperates with RNA helicase DHX15 to modify RNAs with highly structured 5′ termini

2018 ◽  
Vol 373 (1762) ◽  
pp. 20180161 ◽  
Author(s):  
Diana Toczydlowska-Socha ◽  
Magdalena M. Zielinska ◽  
Malgorzata Kurkowska ◽  
Astha ◽  
Catarina F. Almeida ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Degradation ◽  
Rna Modification ◽  
Structure Characteristic ◽  
Helicase Activity ◽  
Theme Issue ◽  
Rna Capping ◽  
Advantageous Effect

The 5′-cap structure, characteristic for RNA polymerase II-transcribed RNAs, plays important roles in RNA metabolism. In humans, RNA cap formation includes post-transcriptional modification of the first transcribed nucleotide by RNA cap1 methyltransferase (CMTr1). Here, we report that CMTr1 activity is hindered towards RNA substrates with highly structured 5′ termini. We found that CMTr1 binds ATP-dependent RNA DHX15 helicase and that this interaction, mediated by the G-patch domain of CMTr1, has an advantageous effect on CMTr1 activity towards highly structured RNA substrates. The effect of DHX15 helicase activity is consistent with the strength of the secondary structure that has to be removed for CMTr1 to access the 5′-terminal residues in a single-stranded conformation. This is, to our knowledge, the first demonstration of the involvement of DHX15 in post-transcriptional RNA modification, and the first example of a molecular process in which DHX15 directly affects the activity of another enzyme. Our findings suggest a new mechanism underlying the regulatory role of DHX15 in the RNA capping process. RNAs with highly structured 5′ termini constitute a significant fraction of the human transcriptome. Hence, CMTr1–DHX15 cooperation is likely to be important for the metabolism of RNA polymerase II-transcribed RNAs. This article is part of the theme issue ‘5′ and 3′ modifications controlling RNA degradation’.

scholarly journals Budding Yeast CTDK-I Is Required for DNA Damage-Induced Transcription

2003 ◽  
Vol 2 (2) ◽  
pp. 274-283 ◽  
Author(s):  
Denis Ostapenko ◽  
Mark J. Solomon
Keyword(s):  
Dna Damage ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Large Scale ◽  
Large Subunit ◽  
Growth Conditions ◽  
Dna Damaging Agents ◽  
Irradiation Treatment ◽  
Mutant Cells

ABSTRACT CTDK-I phosphorylates the C-terminal domain (CTD) of the large subunit of yeast RNA polymerase II in a reaction that stimulates transcription elongation. Mutations in CTDK-I subunits—Ctk1p, Ctk2p, and Ctk3p—confer conditional phenotypes. In this study, we examined the role of CTDK-I in the DNA damage response. We found that mutation of individual CTDK-I subunits rendered yeast sensitive to hydroxyurea (HU) and UV irradiation. Treatment with DNA-damaging agents increased phosphorylation of Ser2 within the CTD repeats in wild-type but not in ctk1Δ mutant cells. Using microarray hybridization, we identified genes whose transcription following DNA damage is Ctk1p dependent, including several DNA repair and stress response genes. Following HU treatment, the level of Ser2-phosphorylated RNA polymerase II increased both globally and on the CTDK-I-regulated genes. The pleiotropic phenotypes of ctk mutants suggest that CTDK-I activity is essential during large-scale transcriptional repatterning under stress and unfavorable growth conditions.

The role of RNA-polymerase II transcription in embryonic nucleologenesis by bovine embryos

Biologia ◽  
2010 ◽  
Vol 65 (3) ◽  
Author(s):  
Mária Kovalská ◽  
Ida Petrovičová ◽  
František Strejček ◽  
Marian Adamkov ◽  
Erika Halašová ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
De Novo ◽  
Control Group ◽  
Bovine Embryos ◽  
Embryonic Genome Activation ◽  
Embryonic Genome ◽  
Autoradiographic Labeling ◽  
Genome Activation

AbstractThe early stages of embryonic development are maternally driven. As development proceeds, maternally inherited informational molecules decay, and embryogenesis becomes dependent on de novo synthesized RNAs of embryonic genome. The aim of the present study is to investigate the role of de novo transcription in the development of embryos during embryonic genome activation. Autoradiography for detection of transcriptional activity and transmission electron microscopy were applied in in vitro produced bovine embryos cultured to the late 8-cell stage with or without (control group) α-amanitin, specific inhibitor of RNA-polymerases II and III transcription. The α-amanitin (AA) groups presented three sets of embryos cultivated with AA in different time intervals (6, 9 and 12 h). In control group, nucleoplasm and nucleolar structures displayed strong autoradiographic labeling and showed initial development of fibrillo-granular nucleoli. In α-amanitin groups, lack of autoradiographic labeling and disintegrated nucleolus precursor bodies (NPBs) stage were observed. Inhibition of RNA polymerase II (RNA pol II) already in the early phases of embryonic genome activation has detrimental effect on nucleolar formation and embryo survival, what was shown for the first time.

scholarly journals Active transcription and essential role of RNA polymerase II at the centromere during mitosis

2012 ◽  
Vol 109 (6) ◽  
pp. 1979-1984 ◽  
Author(s):  
F. L. Chan ◽  
O. J. Marshall ◽  
R. Saffery ◽  
B. Won Kim ◽  
E. Earle ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Essential Role ◽  
Active Transcription
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