scholarly journals CTCF Interacts with and Recruits the Largest Subunit of RNA Polymerase II to CTCF Target Sites Genome-Wide

2007 ◽  
Vol 27 (5) ◽  
pp. 1631-1648 ◽  
Author(s):  
Igor Chernukhin ◽  
Shaharum Shamsuddin ◽  
Sung Yun Kang ◽  
Rosita Bergström ◽  
Yoo-Wook Kwon ◽  
...  

ABSTRACT CTCF is a transcription factor with highly versatile functions ranging from gene activation and repression to the regulation of insulator function and imprinting. Although many of these functions rely on CTCF-DNA interactions, it is an emerging realization that CTCF-dependent molecular processes involve CTCF interactions with other proteins. In this study, we report the association of a subpopulation of CTCF with the RNA polymerase II (Pol II) protein complex. We identified the largest subunit of Pol II (LS Pol II) as a protein significantly colocalizing with CTCF in the nucleus and specifically interacting with CTCF in vivo and in vitro. The role of CTCF as a link between DNA and LS Pol II has been reinforced by the observation that the association of LS Pol II with CTCF target sites in vivo depends on intact CTCF binding sequences. “Serial” chromatin immunoprecipitation (ChIP) analysis revealed that both CTCF and LS Pol II were present at the β-globin insulator in proliferating HD3 cells but not in differentiated globin synthesizing HD3 cells. Further, a single wild-type CTCF target site (N-Myc-CTCF), but not the mutant site deficient for CTCF binding, was sufficient to activate the transcription from the promoterless reporter gene in stably transfected cells. Finally, a ChIP-on-ChIP hybridization assay using microarrays of a library of CTCF target sites revealed that many intergenic CTCF target sequences interacted with both CTCF and LS Pol II. We discuss the possible implications of our observations with respect to plausible mechanisms of transcriptional regulation via a CTCF-mediated direct link of LS Pol II to the DNA.

2001 ◽  
Vol 276 (15) ◽  
pp. 12266-12273 ◽  
Author(s):  
Wenxiang Wei ◽  
Dorjbal Dorjsuren ◽  
Yong Lin ◽  
Weiping Qin ◽  
Takahiro Nomura ◽  
...  

The general transcription factor IIF (TFIIF) assembled in the initiation complex, and RAP30 of TFIIF, have been shown to associate with RNA polymerase II (pol II), although it remains unclear which pol II subunit is responsible for the interaction. We examined whether TFIIF interacts with RNA polymerase II subunit 5 (RPB5), the exposed domain of which binds transcriptional regulatory factors such as hepatitis B virus X protein and a novel regulatory protein, RPB5-mediating protein. The results demonstrated that RPB5 directly binds RAP30in vitrousing purified recombinant proteins andin vivoin COS1 cells transiently expressing recombinant RAP30 and RPB5. The RAP30-binding region was mapped to the central region (amino acids (aa) 47–120) of RPB5, which partly overlaps the hepatitis B virus X protein-binding region. Although the middle part (aa 101–170) and the N-terminus (aa 1–100) of RAP30 independently bound RPB5, the latter was not involved in the RPB5 binding when RAP30 was present in TFIIF complex. Scanning of the middle part of RAP30 by clustered alanine substitutions and then point alanine substitutions pinpointed two residues critical for the RPB5 binding inin vitroandin vivoassays. Wild type but not mutants Y124A and Q131A of RAP30 coexpressed with FLAG-RAP74 efficiently recovered endogenous RPB5 to the FLAG-RAP74-bound anti-FLAG M2 resin. The recovered endogenous RPB5 is assembled in pol II as demonstrated immunologically. Interestingly, coexpression of the central region of RPB5 and wild type RAP30 inhibited recovery of endogenous pol II to the FLAG-RAP74-bound M2 resin, strongly suggesting that the RAP30-binding region of RPB5 inhibited the association of TFIIF and pol II. The exposed domain of RPB5 interacts with RAP30 of TFIIF and is important for the association between pol II and TFIIF.


2001 ◽  
Vol 21 (8) ◽  
pp. 2736-2742 ◽  
Author(s):  
Joseph V. Geisberg ◽  
Frank C. Holstege ◽  
Richard A. Young ◽  
Kevin Struhl

ABSTRACT NC2 (Dr1-Drap1 or Bur6-Ydr1) has been characterized in vitro as a general negative regulator of RNA polymerase II (Pol II) transcription that interacts with TATA-binding protein (TBP) and inhibits its function. Here, we show that NC2 associates with promoters in vivo in a manner that correlates with transcriptional activity and with occupancy by basal transcription factors. NC2 rapidly associates with promoters in response to transcriptional activation, and it remains associated under conditions in which transcription is blocked after assembly of the Pol II preinitiation complex. NC2 positively and negatively affects approximately 17% of Saccharomyces cerevisiaegenes in a pattern that resembles the response to general environmental stress. Relative to TBP, NC2 occupancy is high at promoters where NC2 is positively required for normal levels of transcription. Thus, NC2 is associated with the Pol II preinitiation complex, and it can play a direct and positive role at certain promoters in vivo.


2004 ◽  
Vol 24 (7) ◽  
pp. 2863-2874 ◽  
Author(s):  
Thomas C. Tubon ◽  
William P. Tansey ◽  
Winship Herr

ABSTRACT The general transcription factor TFIIB is a highly conserved and essential component of the eukaryotic RNA polymerase II (pol II) transcription initiation machinery. It consists of a single polypeptide with two conserved structural domains: an amino-terminal zinc ribbon structure (TFIIBZR) and a carboxy-terminal core (TFIIBCORE). We have analyzed the role of the amino-terminal region of human TFIIB in transcription in vivo and in vitro. We identified a small nonconserved surface of the TFIIBZR that is required for pol II transcription in vivo and for different types of basal pol II transcription in vitro. Consistent with a general role in transcription, this TFIIBZR surface is directly involved in the recruitment of pol II to a TATA box-containing promoter. Curiously, although the amino-terminal human TFIIBZR domain can recruit both human pol II and yeast (Saccharomyces cerevisiae) pol II, the yeast TFIIB amino-terminal region recruits yeast pol II but not human pol II. Thus, a critical process in transcription from many different promoters—pol II recruitment—has changed in sequence specificity during eukaryotic evolution.


2011 ◽  
Vol 286 (41) ◽  
pp. 35553-35561 ◽  
Author(s):  
Lidija Staresincic ◽  
Jane Walker ◽  
A. Barbara Dirac-Svejstrup ◽  
Richard Mitter ◽  
Jesper Q. Svejstrup

We identified XAB1 in a proteomic screen for factors that interact with human RNA polymerase II (RNAPII). Because XAB1 has a conserved Saccharomyces cerevisiae homologue called Npa3, yeast genetics and biochemical analysis were used to dissect the significance of the interaction. Degron-dependent Npa3 depletion resulted in genome-wide transcription decreases, correlating with a loss of RNAPII from genes as measured by chromatin immunoprecipitation. Surprisingly, however, transcription in vitro was unaffected by Npa3, suggesting that it affects a process that is not required for transcription in yeast extracts. Indeed, Npa3 depletion in vivo affects nuclear localization of RNAPII; the polymerase accumulates in the cytoplasm. Npa3 is a member of the GPN-LOOP family of GTPases. Npa3 mutants that either cannot bind GTP or that bind but cannot hydrolyze it are inviable and unable to support nuclear transport of RNAPII. Surprisingly, we were unable to detect interactions between Npa3 and proteins in the classical importin α/β pathway for nuclear import. Interestingly, Npa3-RNAPII binding is significantly increased by the addition of GTP or its slowly hydrolyzable analogue guanosine 5′-3-O-(thio)triphosphate (GTPγS). Moreover, the Npa3 mutant that binds GTP, but cannot hydrolyze it, binds RNAPII even in the absence of added GTP, whereas the mutant that cannot bind GTP is unable to bind the polymerase. Together, our data suggest that Npa3 defines an unconventional pathway for nuclear import of RNAPII, which involves GTP-dependent binding of Npa3 to the polymerase.


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.


2009 ◽  
Vol 29 (20) ◽  
pp. 5455-5464 ◽  
Author(s):  
Kira Glover-Cutter ◽  
Stéphane Larochelle ◽  
Benjamin Erickson ◽  
Chao Zhang ◽  
Kevan Shokat ◽  
...  

ABSTRACT The function of human TFIIH-associated Cdk7 in RNA polymerase II (Pol II) transcription and C-terminal domain (CTD) phosphorylation was investigated in analogue-sensitive Cdk7 as/as mutant cells where the kinase can be inhibited without disrupting TFIIH. We show that both Cdk7 and Cdk9/PTEFb contribute to phosphorylation of Pol II CTD Ser5 residues on transcribed genes. Cdk7 is also a major kinase of CTD Ser7 on Pol II at the c-fos and U snRNA genes. Furthermore, TFIIH and recombinant Cdk7-CycH-Mat1 as well as recombinant Cdk9-CycT1 phosphorylated CTD Ser7 and Ser5 residues in vitro. Inhibition of Cdk7 in vivo suppressed the amount of Pol II accumulated at 5′ ends on several genes including c-myc, p21, and glyceraldehyde-3-phosphate dehydrogenase genes, indicating reduced promoter-proximal pausing or polymerase “leaking” into the gene. Consistent with a 5′ pausing defect, Cdk7 inhibition reduced recruitment of the negative elongation factor NELF at start sites. A role of Cdk7 in regulating elongation is further suggested by enhanced histone H4 acetylation and diminished histone H4 trimethylation on lysine 36—two marks of elongation—within genes when the kinase was inhibited. Consistent with a new role for TFIIH at 3′ ends, it was detected within genes and 3′-flanking regions, and Cdk7 inhibition delayed pausing and transcription termination.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Natalia Petrenko ◽  
Yi Jin ◽  
Liguo Dong ◽  
Koon Ho Wong ◽  
Kevin Struhl

Transcription by RNA polymerase II requires assembly of a preinitiation complex (PIC) composed of general transcription factors (GTFs) bound at the promoter. In vitro, some GTFs are essential for transcription, whereas others are not required under certain conditions. PICs are stable in the absence of nucleotide triphosphates, and subsets of GTFs can form partial PICs. By depleting individual GTFs in yeast cells, we show that all GTFs are essential for TBP binding and transcription, suggesting that partial PICs do not exist at appreciable levels in vivo. Depletion of FACT, a histone chaperone that travels with elongating Pol II, strongly reduces PIC formation and transcription. In contrast, TBP-associated factors (TAFs) contribute to transcription of most genes, but TAF-independent transcription occurs at substantial levels, preferentially at promoters containing TATA elements. PICs are absent in cells deprived of uracil, and presumably UTP, suggesting that transcriptionally inactive PICs are removed from promoters in vivo.


2017 ◽  
Author(s):  
Pabitra K. Parua ◽  
Gregory T. Booth ◽  
Miriam Sansó ◽  
Bradley Benjamin ◽  
Jason C. Tanny ◽  
...  

The end of the RNA polymerase II (Pol II) transcription cycle is strictly regulated to ensure proper mRNA maturation and prevent interference between neighboring genes1. Pol II slowing downstream of the cleavage and polyadenylation signal (CPS) leads to recruitment of cleavage and polyadenylation factors and termination2, but how this chain of events is initiated remains unclear. In a chemical-genetic screen, we identified protein phosphatase 1 (PP1) isoforms as substrates of human positive transcription elongation factor b (P-TEFb), the cyclin-dependent kinase 9 (Cdk9)-cyclin T1 complex3. Here we show that Cdk9 and PP1 govern phosphorylation of the conserved transcription factor Spt5 in the fission yeast Schizosaccharomyces pombe. Cdk9 phosphorylates both Spt5 and a negative regulatory site on the PP1 isoform Dis24. Sites phosphorylated by Cdk9 in the Spt5 carboxy-terminal domain (CTD) are dephosphorylated by Dis2 in vitro, and Cdk9 inhibition in vivo leads to rapid Spt5 dephosphorylation that is retarded by concurrent Dis2 inactivation. Chromatin immunoprecipitation and sequencing (ChIP-seq) analysis indicates that Spt5 is dephosphorylated as transcription complexes traverse the CPS, prior to or concomitant with slowing of Pol II5. A Dis2-inactivating mutation stabilizes Spt5 phosphorylation (pSpt5) on chromatin, promotes transcription beyond the normal termination zone detected by precision run-on transcription and sequencing (PRO-seq)6, and is suppressed by ablation of Cdk9 target sites in Spt5. These results support a model whereby the transition of Pol II from elongation to termination is regulated by opposing activities of Cdk9 and Dis2 towards their common substrate Spt5—a bistable switch analogous to a Cdk1-PP1 module that controls mitotic progression4.


2001 ◽  
Vol 152 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Livio Pellizzoni ◽  
Bernard Charroux ◽  
Juri Rappsilber ◽  
Matthias Mann ◽  
Gideon Dreyfuss

The survival motor neuron (SMN) protein, the protein product of the spinal muscular atrophy (SMA) disease gene, plays a role in the assembly and regeneration of small nuclear ribonucleoproteins (snRNPs) and spliceosomes. By nanoelectrospray mass spectrometry, we identified RNA helicase A (RHA) as an SMN complex–associated protein. RHA is a DEAH box RNA helicase which binds RNA polymerase II (pol II) and reportedly functions in transcription. SMN interacts with RHA in vitro, and this interaction is impaired in mutant SMNs found in SMA patients. Coimmunoprecipitation demonstrated that the SMN complex is associated with pol II, snRNPs, and RHA in vivo. In vitro experiments suggest that RHA mediates the association of SMN with the COOH-terminal domain of pol II. Moreover, transfection of cells with a dominant negative mutant of SMN, SMNΔN27, causes accumulation of pol II, snRNPs, and RHA in nuclear structures that contain the known markers of gems and coiled bodies, and inhibits RNA pol I and pol II transcription in vivo. These findings indicate a functional as well as physical association of the SMN complex with pol II and suggest a role for the SMN complex in the assembly of the pol II transcription/processing machinery.


2004 ◽  
Vol 24 (4) ◽  
pp. 1721-1735 ◽  
Author(s):  
Ying Liu ◽  
Charles Kung ◽  
James Fishburn ◽  
Aseem Z. Ansari ◽  
Kevan M. Shokat ◽  
...  

ABSTRACT Three cyclin-dependent kinases, CDK7, -8, and -9, are specifically involved in transcription by RNA polymerase II (Pol II) and target the Pol II C-terminal domain (CTD). The role of CDK7 and CDK8 kinase activity in transcription has been unclear, with CDK7 shown to have variable effects on transcription and CDK8 suggested to repress transcription and/or to target other gene-specific factors. Using a chemical genetics approach, the Saccharomyces cerevisiae homologs of these kinases, Kin28 and Srb10, were engineered to respond to a specific inhibitor and the inhibitor was used to test the role of these kinases in transcription in vivo and in vitro. In vitro, these kinases can both promote transcription, with up to 70% of transcription abolished when both kinases are inhibited together. Similarly, in vivo inhibition of both kinases together gives the strongest decrease in transcription, as measured by chromatin immunoprecipitation of Pol II. Kin28 and Srb10 also have overlapping roles in promoting ATP-dependent dissociation of the preinitiation complex (PIC) into the Scaffold complex. Using the engineered kinases and an ATP analog, specific kinase substrates within the PIC were identified. In addition to the previously known substrate, the Pol II CTD, it was found that Kin28 phosphorylates two subunits of Mediator and Srb10 targets two subunits of TFIID for phosphorylation.


Sign in / Sign up

Export Citation Format

Share Document