scholarly journals Requirement for Yeast RAD26, a Homolog of the HumanCSB Gene, in Elongation by RNA Polymerase II

2001 ◽  
Vol 21 (24) ◽  
pp. 8651-8656 ◽  
Author(s):  
Sung-Keun Lee ◽  
Sung-Lim Yu ◽  
Louise Prakash ◽  
Satya Prakash

ABSTRACT Mutations in the human CSB gene cause Cockayne syndrome (CS). In addition to increased photosensitivity, CS patients suffer from severe developmental abnormalities, including growth retardation and mental retardation. Whereas a deficiency in the preferential repair of UV lesions from the transcribed strand accounts for the increased photosensitivity of CS patients, the reason for developmental defects in these individuals has remained unclear. Here we provide in vivo evidence for a role of RAD26, the counterpart of the CSB gene in Saccharomyces cerevisiae, in transcription elongation by RNA polymerase II, and in addition we show that under conditions requiring rapid synthesis of new mRNAs, growth is considerably reduced in cells lackingRAD26. These findings implicate a role for CSB in transcription elongation, and they strongly suggest that impaired transcription elongation is the underlying cause of the developmental problems in CS patients.

2002 ◽  
Vol 22 (21) ◽  
pp. 7543-7552 ◽  
Author(s):  
Subhrangsu S. Mandal ◽  
Helen Cho ◽  
Sungjoon Kim ◽  
Kettly Cabane ◽  
Danny Reinberg

ABSTRACT FCP1, a phosphatase specific for the carboxy-terminal domain of RNA polymerase II (RNAP II), was found to stimulate transcript elongation by RNAP II in vitro and in vivo. This activity is independent of and distinct from the elongation-stimulatory activity associated with transcription factor IIF (TFIIF), and the elongation effects of TFIIF and FCP1 were found to be additive. Genetic experiments resulted in the isolation of several distinct fcp1 alleles. One of these alleles was found to suppress the slow-growth phenotype associated with either the reduction of intracellular nucleotide concentrations or the inhibition of other transcription elongation factors. Importantly, this allele of fcp1 was found to be lethal when combined individually with two mutations in the second-largest subunit of RNAP II, which had been shown previously to affect transcription elongation.


Science ◽  
2019 ◽  
Vol 363 (6428) ◽  
pp. 744-747 ◽  
Author(s):  
Haruhiko Ehara ◽  
Tomoya Kujirai ◽  
Yuka Fujino ◽  
Mikako Shirouzu ◽  
Hitoshi Kurumizaka ◽  
...  

RNA polymerase II (RNAPII) transcribes chromosomal DNA that contains multiple nucleosomes. The nucleosome forms transcriptional barriers, and nucleosomal transcription requires several additional factors in vivo. We demonstrate that the transcription elongation factors Elf1 and Spt4/5 cooperatively lower the barriers and increase the RNAPII processivity in the nucleosome. The cryo–electron microscopy structures of the nucleosome-transcribing RNAPII elongation complexes (ECs) reveal that Elf1 and Spt4/5 reshape the EC downstream edge and intervene between RNAPII and the nucleosome. They facilitate RNAPII progression through superhelical location SHL(–1) by adjusting the nucleosome in favor of the forward progression. They suppress pausing at SHL(–5) by preventing the stable RNAPII-nucleosome interaction. Thus, the EC overcomes the nucleosomal barriers while providing a platform for various chromatin functions.


2020 ◽  
pp. jbc.RA120.015876
Author(s):  
Yating Wang ◽  
Liming Hou ◽  
M. Behfar Ardehali ◽  
Robert E. Kingston ◽  
Brian D Dynlacht

Elongin is an RNA polymerase II (RNAPII)-associated factor that has been shown to stimulate transcriptional elongation in vitro. The Elongin complex is thought to be required for transcriptional induction in response to cellular stimuli and to ubiquitinate RNAPII in response to DNA damage. Yet the impact of the Elongin complex on transcription in vivo has not been well studied. Here, we performed comprehensive studies of the role of Elongin A, the largest subunit of the Elongin complex, on RNAPII transcription genome-wide. Our results suggest that Elongin A localizes to actively transcribed regions and potential enhancers, and the level of recruitment correlated with transcription levels. We also identified a large group of factors involved in transcription as Elongin A-associated factors. In addition, we found that loss of Elongin A leads to dramatically reduced levels of Ser2-phosphorylated, but not total, RNAPII, and cells depleted of Elongin A show stronger promoter RNAPII pausing, suggesting that Elongin A may be involved in the release of paused RNAPII. Our RNA-seq studies suggest that loss of Elongin A did not alter global transcription, and unlike prior in vitro studies, we did not observe a dramatic impact on RNAPII elongation rates in our cell-based nascent RNA-seq experiments upon Elongin A depletion. Taken together, our studies provide the first comprehensive analysis of the role of Elongin A in regulating transcription in vivo. Our studies also revealed that unlike prior in vitro findings, depletion of Elongin A has little impact on global transcription profiles and transcription elongation in vivo.


1992 ◽  
Vol 12 (5) ◽  
pp. 2078-2090
Author(s):  
N F Marshall ◽  
D H Price

We have examined elongation by RNA polymerase II initiated at a promoter and have identified two classes of elongation complexes. Following initiation at a promoter, all polymerase molecules enter an abortive mode of elongation. Abortive elongation is characterized by the rapid generation of short transcripts due to pausing of the polymerase followed by termination of transcription. Termination of the early elongation complexes can be suppressed by the addition of 250 mM KCl or 1 mg of heparin per ml soon after initiation. Elongation complexes of the second class carry out productive elongation in which long transcripts can be synthesized. Productive elongation complexes are derived from early paused elongation complexes by the action of a factor which we call P-TEF (positive transcription elongation factor). P-TEF is inhibited by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole at concentrations which have no effect on the initiation of transcription. By using templates immobilized on paramagnetic particles, we show that isolated preinitiation complexes lack P-TEF and give rise to transcription complexes which can carry out only abortive elongation. The ability to carry out productive elongation can be restored to isolated transcription complexes by the addition of P-TEF after initiation. A model is presented which describes the role of elongation factors in the formation and maintenance of elongation complexes. The model is consistent with the available in vivo data concerning control of elongation and is used to predict the outcome of other potential in vitro and in vivo experiments.


1988 ◽  
Vol 8 (10) ◽  
pp. 4389-4394
Author(s):  
T K Kerppola ◽  
C M Kane

We have studied transcription elongation and termination in the human c-myc gene. Transcription of c-myc gene sequences with purified mammalian RNA polymerase II revealed several sites of transcription termination and pausing in the vicinity of the exon 1-intron 1 junction. This region previously has been shown to block transcription elongation in vivo by nuclear run-on analysis (D. Bentley and M. Groudine, Nature [London] 321:702-706, 1986). These sites were recognized by purified RNA polymerase II, and we therefore designated them intrinsic sites of termination and pausing. Two of these sites cause termination of RNA polymerase III transcription as well. RNA polymerase II terminated transcription in a cluster of seven consecutive T residues in the nontranscribed strand and paused during transcription at three additional sites in this region. The intrinsic sites of transcription termination and pausing described here correspond closely to the 3' ends of transcripts synthesized in Xenopus oocytes injected with plasmids containing the c-myc termination region (D. Bentley and M. Groudine, Cell 53:245-256, 1988). This correspondence suggests that the intrinsic recognition of these termination and pause sites by purified RNA polymerase II may play a role in the transcription elongation block observed in vivo.


2002 ◽  
Vol 22 (24) ◽  
pp. 8763-8773 ◽  
Author(s):  
Robert J. Merker ◽  
Hannah L. Klein

ABSTRACT The Saccharomyces cerevisiae hyperrecombination mutation hpr1Δ results in instability of sequences between direct repeats that is dependent on transcription of the repeat. Here it is shown that the HPR1 gene also functions in plasmid stability in the presence of destabilizing transcription elongation. In the hpr1Δ mutant, plasmid instability results from unchecked transcription elongation, which can be suppressed by a strong transcription terminator. The plasmid system has been used to examine in vivo aspects of transcription in the absence of Hpr1p. Nuclear run-on studies suggest that there is an increased RNA polymerase II density in the hpr1Δ mutant strain, but this is not accompanied by an increase in accumulation of cytoplasmic mRNA. Suppression of plasmid instability in hpr1Δ can also be achieved by high-copy expression of the RNA splicing factor SUB2, which has recently been proposed to function in mRNA export, in addition to its role in pre-mRNA splicing. High-copy-number SUB2 expression is accompanied by an increase in message accumulation from the plasmid, suggesting that the mechanism of suppression by Sub2p involves the formation of mature mRNA. Models for the role of Hpr1p in mature mRNA formation and the cause of plasmid instability in the absence of the Hpr1 protein are discussed.


1992 ◽  
Vol 12 (5) ◽  
pp. 2078-2090 ◽  
Author(s):  
N F Marshall ◽  
D H Price

We have examined elongation by RNA polymerase II initiated at a promoter and have identified two classes of elongation complexes. Following initiation at a promoter, all polymerase molecules enter an abortive mode of elongation. Abortive elongation is characterized by the rapid generation of short transcripts due to pausing of the polymerase followed by termination of transcription. Termination of the early elongation complexes can be suppressed by the addition of 250 mM KCl or 1 mg of heparin per ml soon after initiation. Elongation complexes of the second class carry out productive elongation in which long transcripts can be synthesized. Productive elongation complexes are derived from early paused elongation complexes by the action of a factor which we call P-TEF (positive transcription elongation factor). P-TEF is inhibited by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole at concentrations which have no effect on the initiation of transcription. By using templates immobilized on paramagnetic particles, we show that isolated preinitiation complexes lack P-TEF and give rise to transcription complexes which can carry out only abortive elongation. The ability to carry out productive elongation can be restored to isolated transcription complexes by the addition of P-TEF after initiation. A model is presented which describes the role of elongation factors in the formation and maintenance of elongation complexes. The model is consistent with the available in vivo data concerning control of elongation and is used to predict the outcome of other potential in vitro and in vivo experiments.


2006 ◽  
Vol 27 (3) ◽  
pp. 926-936 ◽  
Author(s):  
Mariela Reyes-Reyes ◽  
Michael Hampsey

ABSTRACT The RNA polymerase II (RNAP II) transcription cycle is accompanied by changes in the phosphorylation status of the C-terminal domain (CTD), a reiterated heptapeptide sequence (Y1S2P3T4S5P6S7) present at the C terminus of the largest RNAP II subunit. One of the enzymes involved in this process is Ssu72, a CTD phosphatase with specificity for serine-5-P. Here we report that the ssu72-2-encoded Ssu72-R129A protein is catalytically impaired in vitro and that the ssu72-2 mutant accumulates the serine-5-P form of RNAP II in vivo. An in vitro transcription system derived from the ssu72-2 mutant exhibits impaired elongation efficiency. Mutations in RPB1 and RPB2, the genes encoding the two largest subunits of RNAP II, were identified as suppressors of ssu72-2. The rpb1-1001 suppressor encodes an R1281A replacement, whereas rpb2-1001 encodes an R983G replacement. This information led us to identify the previously defined rpb2-4 and rpb2-10 alleles, which encode catalytically slow forms of RNAP II, as additional suppressors of ssu72-2. Furthermore, deletion of SPT4, which encodes a subunit of the Spt4-Spt5 early elongation complex, also suppresses ssu72-2, whereas the spt5-242 allele is suppressed by rpb2-1001. These results define Ssu72 as a transcription elongation factor. We propose a model in which Ssu72 catalyzes serine-5-P dephosphorylation subsequent to addition of the 7-methylguanosine cap on pre-mRNA in a manner that facilitates the RNAP II transition into the elongation stage of the transcription cycle.


2005 ◽  
Vol 25 (17) ◽  
pp. 7665-7674 ◽  
Author(s):  
Rob D. Chapman ◽  
Marcus Conrad ◽  
Dirk Eick

ABSTRACT The C-terminal domain (CTD) of mammalian RNA polymerase II (Pol II) consists of 52 repeats of the consensus heptapeptide YSPTSPS and links transcription to the processing of pre-mRNA. The length of the CTD and the number of repeats diverging from the consensus sequence have increased through evolution, but their functional importance remains unknown. Here, we show that the deletion of repeats 1 to 3 or 52 leads to cleavage and degradation of the CTD from Pol II in vivo. Including these repeats, however, allowed the construction of stable, synthetic CTDs. To our surprise, polymerases consisting of just consensus repeats could support normal growth and viability of cells. We conclude that all other nonconsensus CTD repeats are dispensable for the transcription and pre-mRNA processing of genes essential for proliferation.


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