scholarly journals Selective kinase inhibition shows that Bur1 (Cdk9) phosphorylates the Rpb1 linker in vivo

2018 ◽  
Author(s):  
Yujin Chun ◽  
Hyunsuk Suh ◽  
Yoo Jin Joo ◽  
Gaelle Batot ◽  
Christopher P. Hill ◽  
...  

Cyclin-dependent kinases play multiple roles in RNA polymerase II transcription. Cdk7/Kin28, Cdk9/Bur1, and Cdk12/Ctk1 phosphorylate the polymerase and other factors to drive the dynamic exchange of initiation and elongation complex components over the transcription cycle. We engineered strains of the yeast Saccharomyces cerevisiae for rapid, specific inactivation of individual kinases by addition of a covalent inhibitor. While effective, the sensitized kinases can display some idiosyncrasies, and inhibition can be surprisingly transient. As expected, inhibition of Cdk7/Kin28 blocked phosphorylation of the Rpb1 C-terminal domain heptad repeats at Serines 5 and 7, which are known target sites, but also at Serine 2. Consistent with our previous results using gene deletions, Cdk12/Ctk1 is the predominant kinase responsible for Serine 2 phosphorylation. Phosphorylation of the Rpb1 linker enhances binding of the Spt6 tSH2 domain, and here we show that Bur1/Cdk9 is the kinase responsible for this modification in vivo.

2019 ◽  
Vol 39 (15) ◽  
Author(s):  
Yujin Chun ◽  
Yoo Jin Joo ◽  
Hyunsuk Suh ◽  
Gaëlle Batot ◽  
Christopher P. Hill ◽  
...  

ABSTRACT Cyclin-dependent kinases play multiple roles in RNA polymerase II transcription. Cdk7/Kin28, Cdk9/Bur1, and Cdk12/Ctk1 phosphorylate the polymerase and other factors to drive the dynamic exchange of initiation and elongation complex components over the transcription cycle. We engineered strains of the yeast Saccharomyces cerevisiae for rapid, specific inactivation of individual kinases by addition of a covalent inhibitor. While effective, the sensitized kinases can display some idiosyncrasies, and inhibition can be surprisingly transient. As expected, inhibition of Cdk7/Kin28 blocked phosphorylation of the Rpb1 C-terminal domain heptad repeats at serines 5 and 7, the known target sites. However, serine 2 phosphorylation was also abrogated, supporting an obligatory sequential phosphorylation mechanism. Consistent with our previous results using gene deletions, Cdk12/Ctk1 is the predominant kinase responsible for serine 2 phosphorylation. Phosphorylation of the Rpb1 linker enhances binding of the Spt6 tandem SH2 domain, and here we show that Bur1/Cdk9 is the kinase responsible for these modifications in vivo.


Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Margaret K Shirra ◽  
Karen M Arndt

AbstractBinding of the TATA-binding protein (TBP) to the promoter is a pivotal step in RNA polymerase II transcription. To identify factors that regulate TBP, we selected for suppressors of a TBP mutant that exhibits promoter-specific defects in activated transcription in vivo and severely reduced affinity for TATA boxes in vitro. Dominant mutations in SNF4 and recessive mutations in REG1, OPI1, and RTF2 were isolated that specifically suppress the inositol auxotrophy of the TBP mutant strains. OPI1 encodes a repressor of INO1 transcription. REG1 and SNF4 encode regulators of the Glc7 phosphatase and Snf1 kinase, respectively, and have well-studied roles in glucose repression. In two-hybrid assays, one SNF4 mutation enhances the interaction between Snf4 and Snf1. Suppression of the TBP mutant by our reg1 and SNF4 mutations appears unrelated to glucose repression, since these mutations do not alleviate repression of SUC2, and glucose levels have little effect on INO1 transcription. Moreover, mutations in TUP1, SSN6, and GLC7, but not HXK2 and MIG1, can cause suppression. Our data suggest that association of TBP with the TATA box may be regulated, directly or indirectly, by a substrate of Snf1. Analysis of INO1 transcription in various mutant strains suggests that this substrate is distinct from Opi1.


2007 ◽  
Vol 27 (13) ◽  
pp. 4641-4651 ◽  
Author(s):  
Junjiang Fu ◽  
Ho-Geun Yoon ◽  
Jun Qin ◽  
Jiemin Wong

ABSTRACT P-TEFb, comprised of CDK9 and a cyclin T subunit, is a global transcriptional elongation factor important for most RNA polymerase II (pol II) transcription. P-TEFb facilitates transcription elongation in part by phosphorylating Ser2 of the heptapeptide repeat of the carboxy-terminal domain (CTD) of the largest subunit of pol II. Previous studies have shown that P-TEFb is subjected to negative regulation by forming an inactive complex with 7SK small RNA and HEXIM1. In an effort to investigate the molecular mechanism by which corepressor N-CoR mediates transcription repression, we identified HEXIM1 as an N-CoR-interacting protein. This finding led us to test whether the P-TEFb complex is regulated by acetylation. We demonstrate that CDK9 is an acetylated protein in cells and can be acetylated by p300 in vitro. Through both in vitro and in vivo assays, we identified lysine 44 of CDK9 as a major acetylation site. We present evidence that CDK9 is regulated by N-CoR and its associated HDAC3 and that acetylation of CDK9 affects its ability to phosphorylate the CTD of pol II. These results suggest that acetylation of CDK9 is an important posttranslational modification that is involved in regulating P-TEFb transcriptional elongation function.


1989 ◽  
Vol 9 (11) ◽  
pp. 4746-4749 ◽  
Author(s):  
D I Chasman ◽  
J Leatherwood ◽  
M Carey ◽  
M Ptashne ◽  
R D Kornberg

Fusion proteins known to activate transcription in vivo were tested for the ability to stimulate transcription in vitro in a recently developed Saccharomyces cerevisiae RNA polymerase II transcription system. One fusion protein, whose activation domain was derived from the herpesvirus transcriptional activator VP16, gave more than 100-fold stimulation in the in vitro system. The order of effects of the various proteins was the same for transcription in vitro and in vivo, suggesting that the natural mechanism of activation is preserved in vitro.


2013 ◽  
Vol 27 (7) ◽  
pp. 767-777 ◽  
Author(s):  
A. Ghamari ◽  
M. P. C. van de Corput ◽  
S. Thongjuea ◽  
W. A. van Cappellen ◽  
W. van IJcken ◽  
...  

2019 ◽  
Vol 47 (12) ◽  
pp. 6250-6268 ◽  
Author(s):  
Olga Calvo ◽  
Nathalie Grandin ◽  
Antonio Jordán-Pla ◽  
Esperanza Miñambres ◽  
Noelia González-Polo ◽  
...  

Abstract Specialized telomeric proteins have an essential role in maintaining genome stability through chromosome end protection and telomere length regulation. In the yeast Saccharomyces cerevisiae, the evolutionary conserved CST complex, composed of the Cdc13, Stn1 and Ten1 proteins, largely contributes to these functions. Here, we report genetic interactions between TEN1 and several genes coding for transcription regulators. Molecular assays confirmed this novel function of Ten1 and further established that it regulates the occupancies of RNA polymerase II and the Spt5 elongation factor within transcribed genes. Since Ten1, but also Cdc13 and Stn1, were found to physically associate with Spt5, we propose that Spt5 represents the target of CST in transcription regulation. Moreover, CST physically associates with Hmo1, previously shown to mediate the architecture of S-phase transcribed genes. The fact that, genome-wide, the promoters of genes down-regulated in the ten1-31 mutant are prefentially bound by Hmo1, leads us to propose a potential role for CST in synchronizing transcription with replication fork progression following head-on collisions.


2004 ◽  
Vol 24 (22) ◽  
pp. 10072-10082 ◽  
Author(s):  
Marcin P. Klejman ◽  
Lloyd A. Pereira ◽  
Hester J. T. van Zeeburg ◽  
Siv Gilfillan ◽  
Michael Meisterernst ◽  
...  

ABSTRACT Transcriptional activity of the TATA-binding protein (TBP) is controlled by a variety of proteins. The BTAF1 protein (formerly known as TAFII170/TAF-172 and the human ortholog of Saccharomyces cerevisiae Mot1p) and the NC2 complex composed of NC2α (DRAP1) and NC2β (Dr1) are able to bind to TBP directly and regulate RNA polymerase II transcription both positively and negatively. Here, we present evidence that the NC2α subunit interacts with BTAF1. In contrast, the NC2β subunit is not able to associate with BTAF1 and seems to interfere with the BTAF1-TBP interaction. Addition of NC2α or the NC2 complex can stimulate the ability of BTAF1 to interact with TBP. This function is dependent on the presence of ATP in cell extracts but does not involve the ATPase activity of BTAF1 nor phosphorylation of NC2α. Together, our results constitute the first evidence of the physical cooperation between BTAF1 and NC2α in TBP regulation and provide a framework to understand transcription functions of NC2α and NC2β in vivo.


2012 ◽  
Vol 32 (17) ◽  
pp. 3594-3607 ◽  
Author(s):  
Z. Ma ◽  
D. Atencio ◽  
C. Barnes ◽  
H. DeFiglio ◽  
S. D. Hanes

Sign in / Sign up

Export Citation Format

Share Document