scholarly journals Evidence that Negative Elongation Factor Represses Transcription Elongation through Binding to a DRB Sensitivity-Inducing Factor/RNA Polymerase II Complex and RNA

2002 ◽  
Vol 22 (9) ◽  
pp. 2918-2927 ◽  
Author(s):  
Yuki Yamaguchi ◽  
Naoto Inukai ◽  
Takashi Narita ◽  
Tadashi Wada ◽  
Hiroshi Handa
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Protein Interactions ◽  
Rna Binding ◽  
Elongation Factor ◽  
Protein Protein Interactions ◽  
Negative Elongation Factor ◽  
Nascent Transcripts

ABSTRACT Negative elongation factor (NELF) is a human transcription factor complex that cooperates with DRB sensitivity-inducing factor (DSIF)/hSpt4-hSpt5 to repress elongation by RNA polymerase II (RNAPII). NELF activity is associated with five polypeptides, including NELF-A, a candidate gene product for Wolf-Hirschhorn syndrome, and NELF-E, a putative RNA-binding protein with arginine-aspartic acid (RD) dipeptide repeats. Here we report several important findings regarding the DSIF/NELF-dependent elongation control. First, we have established an effective method for purifying the active NELF complex using an epitope-tagging technique. Second, the five polypeptides each are important and together are sufficient for its function in vitro. Third, NELF does not bind to either DSIF or RNAPII alone but does bind to the preformed DSIF/RNAPII complex. Fourth, NELF-E has a functional RNA-binding domain, whose mutations impair transcription repression without affecting known protein-protein interactions. Taken together, we propose that NELF causes RNAPII pausing through binding to the DSIF/RNAPII complex and to nascent transcripts. These results also have implications for how DSIF and NELF are regulated in a gene-specific manner in vivo.

scholarly journals Tax Interacts with P-TEFb in a Novel Manner To Stimulate Human T-Lymphotropic Virus Type 1 Transcription

2006 ◽  
Vol 80 (10) ◽  
pp. 4781-4791 ◽  
Author(s):  
Meisheng Zhou ◽  
Hanxin Lu ◽  
Hyeon Park ◽  
Jaime Wilson-Chiru ◽  
Rebecca Linton ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Virus Type ◽  
Protein Interactions ◽  
Elongation Factor ◽  
Protein Protein Interactions ◽  
T Lymphotropic Virus ◽  
Histone Deacetylase 1

ABSTRACT Human T-lymphotropic virus type 1 (HTLV-1) encodes a transcriptional activator, Tax, whose function is essential for viral transcription and replication. Tax transactivates the viral long-terminal repeat through a series of protein-protein interactions which facilitate CREB and CBP/p300 binding. In addition, Tax dissociates transcription repressor histone deacetylase 1 interaction with the CREB response element. The subsequent events through which Tax interacts and communicates with RNA polymerase II and cyclin-dependent kinases (CDKs) are not clearly understood. Here we present evidence that Tax recruits positive transcription elongation factor b (P-TEFb) (CDK9/cyclin T1) to the viral promoter. This recruitment likely involves protein-protein interactions since Tax associates with P-TEFb in vitro as demonstrated by glutathione S-transferase fusion protein pull-down assays and in vivo as shown by coimmunoprecipitation assays. Functionally, small interfering RNA directed toward CDK9 inhibited Tax transactivation in transient assays. Consistent with these findings, the depletion of CDK9 from nuclear extracts inhibited Tax transactivation in vitro. Reconstitution of the reaction with wild-type P-TEFb, but not a kinase-dead mutant, recovered HTLV-1 transcription. Moreover, the addition of the CDK9 inhibitor flavopiridol blocked Tax transactivation in vitro and in vivo. Interestingly, we found that Tax regulates CDK9 kinase activity through a novel autophosphorylation pathway.

scholarly journals EEF1A2 interacts with HSP90AB1 to promote lung adenocarcinoma metastasis via enhancing TGF-β/SMAD signalling

2021 ◽  
Author(s):  
Liqing Jia ◽  
Xiaolu Ge ◽  
Chao Du ◽  
Linna Chen ◽  
Yanhong Zhou ◽  
...  
Keyword(s):  
Lung Adenocarcinoma ◽  
Protein Interactions ◽  
Elongation Factor ◽  
Protein Translation ◽  
Protein Protein Interactions ◽  
Promising Target ◽  
Tgfβ Receptor ◽  
Mesenchymal Transformation

Abstract Background Eukaryotic protein translation elongation factor 1α2 (EEF1A2) is an oncogene that promotes the progression of breast and pancreatic cancer. In this study, we aimed to elucidate the oncogenic function of EEF1A2 in the metastasis of lung adenocarcinoma (LUAD). Methods Immunohistochemistry and western blot were used to study EEF1A2 expression levels in LUAD tissues and cells, respectively. The role of EEF1A2 in LUAD progression were investigated in vitro and in vivo. We identified potential EEF1A2-binding proteins by liquid chromatography-electrospray mass spectrometry (LC-MS)/MS. Protein–protein interactions were determined by immunofluorescence and co-immunoprecipitation (Co-IP). Results In this study, we report that EEF1A2 mediates the epithelial–mesenchymal transformation (EMT), to promote the metastasis of LUAD cells in vitro and in vivo. Moreover, EEF1A2 interacts with HSP90AB1 to increase TGFβ Receptor (TβR)-I, and TβRII expression, followed by enhanced SMAD3 and pSMAD3 expression and nuclear localisation, which promotes the EMT of LUAD cells. Overexpression of EEF1A2 in cancer tissues is associated with poor prognosis and short survival of patients with LUAD. Conclusions These findings underscore the molecular functions of EEF1A2 in LUAD metastasis and indicate that EEF1A2 represents a promising target in the treatment of aggressive LUAD.

Identification of rpo30, a vaccinia virus RNA polymerase gene with structural similarity to a eucaryotic transcription elongation factor

1990 ◽  
Vol 10 (10) ◽  
pp. 5433-5441
Author(s):  
B Y Ahn ◽  
P D Gershon ◽  
E V Jones ◽  
B Moss
Keyword(s):  
Rna Polymerase ◽  
Vaccinia Virus ◽  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
Viral Rna ◽  
In Vitro Translation ◽  
Virus Protein ◽  
Transcriptional Elongation

Eucaryotic transcription factors that stimulate RNA polymerase II by increasing the efficiency of elongation of specifically or randomly initiated RNA chains have been isolated and characterized. We have identified a 30-kilodalton (kDa) vaccinia virus-encoded protein with apparent homology to SII, a 34-kDa mammalian transcriptional elongation factor. In addition to amino acid sequence similarities, both proteins contain C-terminal putative zinc finger domains. Identification of the gene, rpo30, encoding the vaccinia virus protein was achieved by using antibody to the purified viral RNA polymerase for immunoprecipitation of the in vitro translation products of in vivo-synthesized early mRNA selected by hybridization to cloned DNA fragments of the viral genome. Western immunoblot analysis using antiserum made to the vaccinia rpo30 protein expressed in bacteria indicated that the 30-kDa protein remains associated with highly purified viral RNA polymerase. Thus, the vaccinia virus protein, unlike its eucaryotic homolog, is an integral RNA polymerase subunit rather than a readily separable transcription factor. Further studies showed that the expression of rpo30 is regulated by dual early and later promoters.

Genetic interaction between transcription elongation factor TFIIS and RNA polymerase II

1992 ◽  
Vol 12 (9) ◽  
pp. 4142-4152
Author(s):  
J Archambault ◽  
F Lacroute ◽  
A Ruet ◽  
J D Friesen
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Structural Integrity ◽  
Genetic Interaction ◽  
Elongation Factor ◽  
Chemical Mutagenesis ◽  
Yeast Genome ◽  
Transcript Elongation

Little is known about the regions of RNA polymerase II (RNAPII) that are involved in the process of transcript elongation and interaction with elongation factors. One elongation factor, TFIIS, stimulates transcript elongation by binding to RNAPII and facilitating its passage through intrinsic pausing sites in vitro. In Saccharomyces cerevisiae, TFIIS is encoded by the PPR2 gene. Deletion of PPR2 from the yeast genome is not lethal but renders cells sensitive to the uracil analog 6-azauracil (6AU). Here, we show that mutations conferring 6AU sensitivity can also be isolated in the gene encoding the largest subunit of S. cerevisiae RNAPII (RPO21). A screen for mutations in RPO21 that confer 6AU sensitivity identified seven mutations that had been generated by either linker-insertion or random chemical mutagenesis. All seven mutational alterations are clustered within one region of the largest subunit that is conserved among eukaryotic RNAPII. The finding that six of the seven rpo21 mutants failed to grow at elevated temperature underscores the importance of this region for the functional and/or structural integrity of RNAPII. We found that the 6AU sensitivity of the rpo21 mutants can be suppressed by increasing the dosage of the wild-type PPR2 gene, presumably as a result of overexpression of TFIIS. These results are consistent with the proposal that in the rpo21 mutants, the formation of the RNAPII-TFIIS complex is rate limiting for the passage of the mutant enzyme through pausing sites. In addition to implicating a region of the largest subunit of RNAPII in the process of transcript elongation, our observations provide in vivo evidence that TFIIS is involved in transcription by RNAPII.

scholarly journals Mutations in RNA Polymerase II and Elongation Factor SII Severely Reduce mRNA Levels in Saccharomyces cerevisiae

1998 ◽  
Vol 18 (10) ◽  
pp. 5771-5779 ◽  
Author(s):  
J. Cale Lennon ◽  
Megan Wind ◽  
Laura Saunders ◽  
M. Benjamin Hock ◽  
Daniel Reines
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Genetic Interaction ◽  
Elongation Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Mutant Cells ◽  
Rna Levels

ABSTRACT Elongation factor SII interacts with RNA polymerase II and enables it to transcribe through arrest sites in vitro. The set of genes dependent upon SII function in vivo and the effects on RNA levels of mutations in different components of the elongation machinery are poorly understood. Using yeast lacking SII and bearing a conditional allele of RPB2, the gene encoding the second largest subunit of RNA polymerase II, we describe a genetic interaction between SII and RPB2. An SII gene disruption or therpb2-10 mutation, which yields an arrest-prone enzyme in vitro, confers sensitivity to 6-azauracil (6AU), a drug that depresses cellular nucleoside triphosphates. Cells with both mutations had reduced levels of total poly(A)+ RNA and specific mRNAs and displayed a synergistic level of drug hypersensitivity. In cells in which the SII gene was inactivated, rpb2-10 became dominant, as if template-associated mutant RNA polymerase II hindered the ability of wild-type polymerase to transcribe. Interestingly, while 6AU depressed RNA levels in both wild-type and mutant cells, wild-type cells reestablished normal RNA levels, whereas double-mutant cells could not. This work shows the importance of an optimally functioning elongation machinery for in vivo RNA synthesis and identifies an initial set of candidate genes with which SII-dependent transcription can be studied.

scholarly journals Identification of rpo30, a vaccinia virus RNA polymerase gene with structural similarity to a eucaryotic transcription elongation factor.

1990 ◽  
Vol 10 (10) ◽  
pp. 5433-5441 ◽  
Author(s):  
B Y Ahn ◽  
P D Gershon ◽  
E V Jones ◽  
B Moss
Keyword(s):  
Rna Polymerase ◽  
Vaccinia Virus ◽  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
Viral Rna ◽  
In Vitro Translation ◽  
Virus Protein ◽  
Transcriptional Elongation

Eucaryotic transcription factors that stimulate RNA polymerase II by increasing the efficiency of elongation of specifically or randomly initiated RNA chains have been isolated and characterized. We have identified a 30-kilodalton (kDa) vaccinia virus-encoded protein with apparent homology to SII, a 34-kDa mammalian transcriptional elongation factor. In addition to amino acid sequence similarities, both proteins contain C-terminal putative zinc finger domains. Identification of the gene, rpo30, encoding the vaccinia virus protein was achieved by using antibody to the purified viral RNA polymerase for immunoprecipitation of the in vitro translation products of in vivo-synthesized early mRNA selected by hybridization to cloned DNA fragments of the viral genome. Western immunoblot analysis using antiserum made to the vaccinia rpo30 protein expressed in bacteria indicated that the 30-kDa protein remains associated with highly purified viral RNA polymerase. Thus, the vaccinia virus protein, unlike its eucaryotic homolog, is an integral RNA polymerase subunit rather than a readily separable transcription factor. Further studies showed that the expression of rpo30 is regulated by dual early and later promoters.

scholarly journals Genetic interaction between transcription elongation factor TFIIS and RNA polymerase II.

1992 ◽  
Vol 12 (9) ◽  
pp. 4142-4152 ◽  
Author(s):  
J Archambault ◽  
F Lacroute ◽  
A Ruet ◽  
J D Friesen
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Structural Integrity ◽  
Genetic Interaction ◽  
Elongation Factor ◽  
Chemical Mutagenesis ◽  
Yeast Genome ◽  
Transcript Elongation

Little is known about the regions of RNA polymerase II (RNAPII) that are involved in the process of transcript elongation and interaction with elongation factors. One elongation factor, TFIIS, stimulates transcript elongation by binding to RNAPII and facilitating its passage through intrinsic pausing sites in vitro. In Saccharomyces cerevisiae, TFIIS is encoded by the PPR2 gene. Deletion of PPR2 from the yeast genome is not lethal but renders cells sensitive to the uracil analog 6-azauracil (6AU). Here, we show that mutations conferring 6AU sensitivity can also be isolated in the gene encoding the largest subunit of S. cerevisiae RNAPII (RPO21). A screen for mutations in RPO21 that confer 6AU sensitivity identified seven mutations that had been generated by either linker-insertion or random chemical mutagenesis. All seven mutational alterations are clustered within one region of the largest subunit that is conserved among eukaryotic RNAPII. The finding that six of the seven rpo21 mutants failed to grow at elevated temperature underscores the importance of this region for the functional and/or structural integrity of RNAPII. We found that the 6AU sensitivity of the rpo21 mutants can be suppressed by increasing the dosage of the wild-type PPR2 gene, presumably as a result of overexpression of TFIIS. These results are consistent with the proposal that in the rpo21 mutants, the formation of the RNAPII-TFIIS complex is rate limiting for the passage of the mutant enzyme through pausing sites. In addition to implicating a region of the largest subunit of RNAPII in the process of transcript elongation, our observations provide in vivo evidence that TFIIS is involved in transcription by RNAPII.

scholarly journals Spt4 Facilitates the Movement of RNA Polymerase II through the +2 Nucleosomal Barrier

2021 ◽  
Author(s):  
Ülkü Uzun ◽  
Thomas Brown ◽  
Harry Fischl ◽  
Andrew Angel ◽  
Jane Mellor
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
Nucleosome Positioning ◽  
Gene Body ◽  
Precise Position ◽  
Transcription Elongation Factor

AbstractSpt4 is a transcription elongation factor, with homologues in organisms with nucleosomes. Structural and in vitro studies implicate Spt4 in transcription through nucleosomes, yet the in vivo function of Spt4 is unclear. Here we assessed the precise position of Spt4 during transcription and the consequences of loss of Spt4 on RNA polymerase II (RNAPII) dynamics and nucleosome positioning in Saccharomyces cerevisiae. In the absence of Spt4, the spacing between gene-body nucleosomes increases and RNAPII accumulates upstream of the nucleosomal dyad, most dramatically at nucleosome +2. Spt4 associates with elongating RNAPII early in transcription and its association dynamically changes depending on nucleosome positions. Together, our data show that Spt4 regulates early elongation dynamics, participates in co-transcriptional nucleosome positioning, and promotes RNAPII movement through the gene-body nucleosomes, especially the +2 nucleosome.

scholarly journals Control of formation of two distinct classes of RNA polymerase II elongation complexes

1992 ◽  
Vol 12 (5) ◽  
pp. 2078-2090
Author(s):  
N F Marshall ◽  
D H Price
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
In Vivo Experiments ◽  
Rapid Generation ◽  
Transcription Complexes ◽  
Productive Elongation

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.

scholarly journals TFIIH-Associated Cdk7 Kinase Functions in Phosphorylation of C-Terminal Domain Ser7 Residues, Promoter-Proximal Pausing, and Termination by RNA Polymerase II

2009 ◽  
Vol 29 (20) ◽  
pp. 5455-5464 ◽  
Author(s):  
Kira Glover-Cutter ◽  
Stéphane Larochelle ◽  
Benjamin Erickson ◽  
Chao Zhang ◽  
Kevan Shokat ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
Histone H4 ◽  
Pol Ii ◽  
Terminal Domain ◽  
Histone H4 Acetylation ◽  
Flanking Regions

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.

Sign in / Sign up

Export Citation Format

Share Document