Activated transcription independent of the RNA polymerase II holoenzyme in budding yeast

McNeil, J B; Agah, Helga; Bentley, David L.

doi:10.1101/gad.12.16.2510

Cited by 94 publications

(81 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our observation is in line with previous results that showed that Cdk9p, the main CTD Ser-2 kinase, is critical for 3Ј-end processing of mRNAs, but less so for Pol II transcription (25,26). In addition, we demonstrate that the expression of a small portion of the yeast genome is Kin28p-independent, which expands our previous observation (27,28).…”

Section: Discussionsupporting

confidence: 82%

Phosphorylation of the RNA polymerase II C-terminal domain by TFIIH kinase is not essential for transcription of Saccharomyces cerevisiae genome

Hong

Hong²,

Yoo

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Ser-5 phosphorylation of the RNA polymerase II (Pol II) C-terminal domain by TFIIH kinase has been implicated in critical steps in mRNA synthesis, such as Pol II promoter escape and mRNA 5 -capping. However, the general requirement and precise role of TFIIH kinase in Pol II transcription still remain elusive. Here we use a chemical genetics approach to show that, for a majority of budding-yeast genes, specific inhibition of the yeast TFIIH kinase results in a dramatic reduction in both mRNA level and Ser-5 C-terminal domain phosphorylation. Surprisingly, inhibition of TFIIH kinase activity only partially affected both Pol II density and Ser-2 phosphorylation level. The discrepancy between mRNA level and Pol II density is attributed to the defective 5 -capping, which results in the destabilization of mRNAs. Therefore, contrary to the current belief, our study points strongly toward a minor role of TFIIH kinase in Pol II transcription, and a more significant role in mRNA capping in budding yeast.T he C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II) contains a series of YSPTSPS heptad repeats that are multiply-phosphorylated during the eukaryotic transcription cycle. Phosphorylation of the Ser-5 residue of the CTD heptad repeats has been implicated in multiple aspects of mRNA synthesis, such as promoter clearance (for transition from initiation to early elongation) and 5Ј-end capping of pre-mRNA (1). CTD Ser-2 phosphorylation has been implicated in productive elongation and the 3Ј-end processing of the transcript (2). However, it remains unclear whether CTD phosphorylation is required for transcription in general or functions in a promoter-and activatorspecific manner. Moreover, the requirement of Ser-5 phosphorylation for subsequent Ser-2 phosphorylation and transcriptional elongation remains controversial. An earlier study suggested that the CTD Ser-5 phosphorylation by Kin28 does not affect the Ser-2 phosphorylation level (3). In contrast, a recent study suggests that the CTD Ser-5 phosphorylation stimulates Ser-2 phosphorylation by BUR1/BUR2 kinase (4). These issues must be resolved to gain a clear understanding of the role of CTD phosphorylation in Pol II transcription in vivo.Temperature-sensitive mutants of CTD kinases have been used to study the functions of these enzymes in vivo (5). A genome-wide expression analysis using a temperature-sensitive mutant of KIN28, the Saccharomyces cerevisiae TFIIH kinase gene, showed that the loss of Kin28 function resulted in global shutdown of Pol II transcription (6). However, it has been demonstrated that the same mutation also disrupts other subunits in the TFIIH complex upon temperature shift, which makes the unambiguous functional analysis of this kinase difficult (7). Inhibition of CTD kinases with conventional pharmacological inhibitors is also problematic because these agents can nonspecifically inhibit other kinases (8). To overcome these obstacles, we used the ''analog-sensitive'' kinase-mutant strategy to dissect the unique roles of...

show abstract

Section: Discussionsupporting

confidence: 82%

Phosphorylation of the RNA polymerase II C-terminal domain by TFIIH kinase is not essential for transcription of Saccharomyces cerevisiae genome

Hong

Hong²,

Yoo

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Expression of heat-shock genes can occur in the absence of kin-28 in yeast (48,49), and phosphorylation of the CTD at heat shock promoters has been observed in the absence of CDK7 in Chironomus tentans (50). Our finding that hsp16-2 is partially resistant to a reduction in cdk-7 activity is consistent with the idea that CDK7 is not required equally at all promoters.…”

Section: Discussionsupporting

confidence: 80%

cdk-7 is required for mRNA transcription and cell cycle progression in Caenorhabditis elegans embryos

Wallenfang

Seydoux

2002

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

CDK7 is a cyclin-dependent kinase proposed to function in two essential cellular processes: transcription and cell cycle regulation. CDK7 is the kinase subunit of the general transcription factor TFIIH that phosphorylates the C-terminal domain (CTD) of RNA polymerase II, and has been shown to be broadly required for transcription in Saccharomyces cerevisiae. CDK7 can also phosphorylate CDKs that promote cell cycle progression, and has been shown to function as a CDK-activating kinase (CAK) in Schizosaccharomyces pombe and Drosophila melanogaster. That CDK7 performs both functions in metazoans has been difficult to prove because transcription is essential for cell cycle progression in most cells. We have isolated a temperature-sensitive mutation in Caenorhabditis elegans cdk-7 and have used it to analyze the role of cdk-7 in embryonic blastomeres, where cell cycle progression is independent of transcription. Partial loss of cdk-7 activity leads to a general decrease in CTD phosphorylation and embryonic transcription, and severe loss of cdk-7 activity blocks all cell divisions. Our results support a dual role for metazoan CDK7 as a broadly required CTD kinase, and as a CAK essential for cell cycle progression.

show abstract

“…Samples were examined for cell-cycle progression by counting the cells indicated explained simply (see Discussion). Transcript levels of SSA4 and CUP1 were not affected by the overexpression possibly because transcription of both genes is known to be independent of KIN28 (Lee and Lis, 1998;McNeil et al, 1998).…”

Section: Negative Regulation Of Kin28±ccl1 By Srb10mentioning

confidence: 92%

A transcriptional autoregulatory loop for KIN28–CCL1 and SRB10–SRB11, each encoding RNA polymerase II CTD kinase–cyclin pair, stimulates the meiotic development of S. cerevisiae

Ohkuni¹,

Yamashita²

2000

Yeast

View full text Add to dashboard Cite

Alkalization of the medium is associated with and required for the cellular development to meiosis and sporulation in the yeast Saccharomyces cerevisiae. To elucidate the molecular mechanisms for the signi®cance of external alkalization, we isolated mutants defective in division arrest at G 1 phase under an alkaline condition. The mutants obtained had recessive alleles of SRB10 encoding the cyclin (SRB11)-dependent protein kinase that phosphorylates the CTD domain of the largest subunit of RNA polymerase II and negatively regulates the transcriptional initiation of certain genes. A Dsrb11 deletion mutant showed the same cell cycle defect. When shifted to alkali, wild-type cells decreased transcript levels of G 1 -cyclin genes (CLN1 to CLN3) and KIN28±CCL1 (encoding another CTD kinase±cyclin pair which, in contrast, stimulates the promoter clearance and transcriptional elongation in most genes), resulting in the accumulation of G 1 cells and the hypophosphorylated form of RNA polymerase II and in an increase in cell size. However, under the same conditions, a Dsrb10 mutant was defective in these events, except the downregulation of CLN1 and CLN2. The Dsrb10 mutation also in¯uenced on the transcript levels of meiosis-inducing genes called IME1 and IME2: the mutation elevated the transcript level of IME1 but reduced that of IME2, resulting in partial defects in premeiotic DNA synthesis and meiosis. Overexpression of KIN28 and CCL1 in wild-type cells impaired the alkali-induced G 1 arrest and the rate of meiosis and elevated the transcript levels of SRB11 and IME1. These results indicate that a transcriptional autoregulatory loop for KIN28±CCL1 and SRB10±SRB11 is important for G 1 arrest and meiosis. We also found that environmental conditions for meiosis ®nely regulate the transcript levels of KIN28 and CCL1, such that nitrogen starvation ®rst elevates them but subsequent alkalization of medium decreases them.

show abstract

Activated transcription independent of the RNA polymerase II holoenzyme in budding yeast

Cited by 94 publications

References 61 publications

Phosphorylation of the RNA polymerase II C-terminal domain by TFIIH kinase is not essential for transcription of Saccharomyces cerevisiae genome

Phosphorylation of the RNA polymerase II C-terminal domain by TFIIH kinase is not essential for transcription of Saccharomyces cerevisiae genome

cdk-7 is required for mRNA transcription and cell cycle progression in Caenorhabditis elegans embryos

A transcriptional autoregulatory loop for KIN28–CCL1 and SRB10–SRB11, each encoding RNA polymerase II CTD kinase–cyclin pair, stimulates the meiotic development of S. cerevisiae

Contact Info

Product

Resources

About