The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Matija B Peterlin - One of the best experts on this subject based on the ideXlab platform.
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bromodomain and extra terminal bet bromodomain inhibition activate Transcription via transient release of positive Transcription Elongation factor b p tefb from 7sk small nuclear ribonucleoprotein
Journal of Biological Chemistry, 2012Co-Authors: Koen Bartholomeeusen, Koh Fujinaga, Yanhui Xiang, Matija B PeterlinAbstract:By phosphorylating Elongation factors and the C-terminal domain of RNA polymerase II, the positive Transcription Elongation factor b (P-TEFb) is the critical kinase for Transcription Elongation and co-Transcriptional processing of eukaryotic genes. It exists in inactive small nuclear ribonucleoprotein (7SK snRNP) and active (free P-TEFb) complexes in cells. The P-TEFb equilibrium determines the state of cellular activation, proliferation, and differentiation. Free P-TEFb, which is required for growth, can be recruited to RNA polymerase II via Transcription factors, BRD4, or the super Elongation complex (SEC). UV light, various signaling cascades, Transcriptional blockade, or compounds such as hexamethylene bisacetamide (HMBA), suberoylanilide hydroxamic acid (SAHA), and other histone deacetylase inhibitors lead to a rapid release of free P-TEFb, followed by its reassembly into the 7SK snRNP. As a consequence, Transcription of HEXIM1, a critical 7SK snRNP subunit, and HIV is induced. In this study, we found that a bromodomain and extra-terminal (BET) bromodomain inhibitor, JQ1, which inhibits BRD4 by blocking its association with chromatin, also leads to the rapid release of free P-TEFb from the 7SK snRNP. Indeed, JQ1 transiently increased levels of free P-TEFb and BRD4·P-TEFb and SEC·P-TEFb complexes in cells. As a consequence, the levels of HEXIM1 and HIV proteins rose. Importantly, the knockdown of ELL2, a subunit of the SEC, blocked the ability of JQ1 to increase HIV Transcription. Finally, the effects of JQ1 and HMBA or SAHA on the P-TEFb equilibrium were cooperative. We conclude that HMBA, SAHA, and JQ1 affect Transcription Elongation by a similar and convergent mechanism.
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cap binding protein complex links pre mrna capping to Transcription Elongation and alternative splicing through positive Transcription Elongation factor b p tefb
Journal of Biological Chemistry, 2011Co-Authors: Tina Lenasi, Matija B Peterlin, Matjaz BarboricAbstract:Promoter-proximal pausing of RNAPII coincides with the formation of the cap structure at the 5′ end of pre-mRNA, which is bound by the cap-binding protein complex (CBC). Although the positive Transcription Elongation factor b (P-TEFb) stimulates the release of RNAPII from pausing and promotes Transcription Elongation and alternative splicing by phosphorylating the RNAPII C-terminal domain at Ser2 (S2-P RNAPII), it is unknown whether CBC facilitates these events. In this study, we report that CBC interacts with P-TEFb and Transcriptionally engaged RNAPII and is globally required for optimal levels of S2-P RNAPII. Quantitative nascent RNA immunoprecipitation and ChIP experiments reveal that depletion of CBC attenuates HIV-1 Tat transactivation and impedes Transcription Elongation of investigated CBC-dependent endogenous genes by decreasing the levels of P-TEFb and S2-P RNAPII, leading to accumulation of RNAPII in the body of these genes. Finally, CBC is essential for the promotion of alternative splicing through facilitating P-TEFb, S2-P RNAPII, and splicing factor 2/alternative splicing factor occupancy at a splicing minigene. These findings disclose a vital role of CBC in connecting pre-mRNA capping to Transcription Elongation and alternative splicing via P-TEFb.
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cap binding protein complex links pre mrna capping to Transcription Elongation and alternative splicing through
2011Co-Authors: Tina Lenasi, Matija B Peterlin, Matjaz BarboricAbstract:Promoter-proximal pausing of RNAPII coincides with theformationofthecapstructureatthe5 endofpre-mRNA,whichis bound by the cap-binding protein complex (CBC). Althoughthe positive Transcription Elongation factor b (P-TEFb) stimu-lates the release of RNAPII from pausing and promotes tran-scription Elongation and alternative splicing by phosphory-latingtheRNAPIIC-terminaldomainatSer2 (S2-PRNAPII),itisunknownwhetherCBCfacilitatestheseevents.Inthisstudy,wereport that CBC interacts with P-TEFb and Transcriptionallyengaged RNAPII and is globally required for optimal levels ofS2-P RNAPII. Quantitative nascent RNA immunoprecipitationand ChIP experiments reveal that depletion of CBC attenuatesHIV-1 Tat transactivation and impedes Transcription elonga-tion of investigated CBC-dependent endogenous genes bydecreasing the levels of P-TEFb and S2-P RNAPII, leading toaccumulation of RNAPII in the body of these genes. Finally,CBC is essential for the promotion of alternative splicingthrough facilitating P-TEFb, S2-P RNAPII, and splicing factor2/alternative splicing factor occupancy at a splicing minigene.These findings disclose a vital role of CBC in connectingpre-mRNA capping to Transcription Elongation and alternativesplicing via P-TEFb.
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7sk snrnp p tefb couples Transcription Elongation with alternative splicing and is essential for vertebrate development
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Matjaz Barboric, Tina Lenasi, Hui Chen, Eric B Johansen, Su Guo, Matija B PeterlinAbstract:Eukaryotic gene expression is commonly controlled at the level of RNA polymerase II (RNAPII) pausing subsequent to Transcription initiation. Transcription Elongation is stimulated by the positive Transcription Elongation factor b (P-TEFb) kinase, which is suppressed within the 7SK small nuclear ribonucleoprotein (7SK snRNP). However, the biogenesis and functional significance of 7SK snRNP remain poorly understood. Here, we report that LARP7, BCDIN3, and the noncoding 7SK small nuclear RNA (7SK) are vital for the formation and stability of a cell stress-resistant core 7SK snRNP. Our functional studies demonstrate that 7SK snRNP is not only critical for controlling Transcription Elongation, but also for regulating alternative splicing of pre-mRNAs. Using a transient expression splicing assay, we find that 7SK snRNP disintegration promotes inclusion of an alternative exon via the increased occupancy of P-TEFb, Ser2-phosphorylated (Ser2-P) RNAPII, and the splicing factor SF2/ASF at the minigene. Importantly, knockdown of larp7 or bcdin3 orthologues in zebrafish embryos destabilizes 7SK and causes severe developmental defects and aberrant splicing of analyzed transcripts. These findings reveal a key role for P-TEFb in coupling Transcription Elongation with alternative splicing, and suggest that maintaining core 7SK snRNP is essential for vertebrate development.
Matjaz Barboric - One of the best experts on this subject based on the ideXlab platform.
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cap binding protein complex links pre mrna capping to Transcription Elongation and alternative splicing through positive Transcription Elongation factor b p tefb
Journal of Biological Chemistry, 2011Co-Authors: Tina Lenasi, Matija B Peterlin, Matjaz BarboricAbstract:Promoter-proximal pausing of RNAPII coincides with the formation of the cap structure at the 5′ end of pre-mRNA, which is bound by the cap-binding protein complex (CBC). Although the positive Transcription Elongation factor b (P-TEFb) stimulates the release of RNAPII from pausing and promotes Transcription Elongation and alternative splicing by phosphorylating the RNAPII C-terminal domain at Ser2 (S2-P RNAPII), it is unknown whether CBC facilitates these events. In this study, we report that CBC interacts with P-TEFb and Transcriptionally engaged RNAPII and is globally required for optimal levels of S2-P RNAPII. Quantitative nascent RNA immunoprecipitation and ChIP experiments reveal that depletion of CBC attenuates HIV-1 Tat transactivation and impedes Transcription Elongation of investigated CBC-dependent endogenous genes by decreasing the levels of P-TEFb and S2-P RNAPII, leading to accumulation of RNAPII in the body of these genes. Finally, CBC is essential for the promotion of alternative splicing through facilitating P-TEFb, S2-P RNAPII, and splicing factor 2/alternative splicing factor occupancy at a splicing minigene. These findings disclose a vital role of CBC in connecting pre-mRNA capping to Transcription Elongation and alternative splicing via P-TEFb.
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cap binding protein complex links pre mrna capping to Transcription Elongation and alternative splicing through
2011Co-Authors: Tina Lenasi, Matija B Peterlin, Matjaz BarboricAbstract:Promoter-proximal pausing of RNAPII coincides with theformationofthecapstructureatthe5 endofpre-mRNA,whichis bound by the cap-binding protein complex (CBC). Althoughthe positive Transcription Elongation factor b (P-TEFb) stimu-lates the release of RNAPII from pausing and promotes tran-scription Elongation and alternative splicing by phosphory-latingtheRNAPIIC-terminaldomainatSer2 (S2-PRNAPII),itisunknownwhetherCBCfacilitatestheseevents.Inthisstudy,wereport that CBC interacts with P-TEFb and Transcriptionallyengaged RNAPII and is globally required for optimal levels ofS2-P RNAPII. Quantitative nascent RNA immunoprecipitationand ChIP experiments reveal that depletion of CBC attenuatesHIV-1 Tat transactivation and impedes Transcription elonga-tion of investigated CBC-dependent endogenous genes bydecreasing the levels of P-TEFb and S2-P RNAPII, leading toaccumulation of RNAPII in the body of these genes. Finally,CBC is essential for the promotion of alternative splicingthrough facilitating P-TEFb, S2-P RNAPII, and splicing factor2/alternative splicing factor occupancy at a splicing minigene.These findings disclose a vital role of CBC in connectingpre-mRNA capping to Transcription Elongation and alternativesplicing via P-TEFb.
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7sk snrnp p tefb couples Transcription Elongation with alternative splicing and is essential for vertebrate development
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Matjaz Barboric, Tina Lenasi, Hui Chen, Eric B Johansen, Su Guo, Matija B PeterlinAbstract:Eukaryotic gene expression is commonly controlled at the level of RNA polymerase II (RNAPII) pausing subsequent to Transcription initiation. Transcription Elongation is stimulated by the positive Transcription Elongation factor b (P-TEFb) kinase, which is suppressed within the 7SK small nuclear ribonucleoprotein (7SK snRNP). However, the biogenesis and functional significance of 7SK snRNP remain poorly understood. Here, we report that LARP7, BCDIN3, and the noncoding 7SK small nuclear RNA (7SK) are vital for the formation and stability of a cell stress-resistant core 7SK snRNP. Our functional studies demonstrate that 7SK snRNP is not only critical for controlling Transcription Elongation, but also for regulating alternative splicing of pre-mRNAs. Using a transient expression splicing assay, we find that 7SK snRNP disintegration promotes inclusion of an alternative exon via the increased occupancy of P-TEFb, Ser2-phosphorylated (Ser2-P) RNAPII, and the splicing factor SF2/ASF at the minigene. Importantly, knockdown of larp7 or bcdin3 orthologues in zebrafish embryos destabilizes 7SK and causes severe developmental defects and aberrant splicing of analyzed transcripts. These findings reveal a key role for P-TEFb in coupling Transcription Elongation with alternative splicing, and suggest that maintaining core 7SK snRNP is essential for vertebrate development.
Andres Aguilera - One of the best experts on this subject based on the ideXlab platform.
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genome instability and Transcription Elongation impairment in human cells depleted of tho trex
PLOS Genetics, 2011Co-Authors: Maria S Dominguezsanchez, Sonia Barroso, Belen Gomezgonzalez, Rosa Luna, Andres AguileraAbstract:THO/TREX connects Transcription with genome integrity in yeast, but a role of mammalian THO in these processes is uncertain, which suggests a differential implication of mRNP biogenesis factors in genome integrity in yeast and humans. We show that human THO depletion impairs Transcription Elongation and mRNA export and increases instability associated with DNA breaks, leading to hyper-recombination and γH2AX and 53BP1 foci accumulation. This is accompanied by replication alteration as determined by DNA combing. Genome instability is R-loop–dependent, as deduced from the ability of the AID enzyme to increase DNA damage and of RNaseH to reduce it, or from the enhancement of R-loop–dependent class-switching caused by THOC1-depletion in CH12 murine cells. Therefore, mammalian THO prevents R-loop formation and has a role in genome dynamics and function consistent with an evolutionary conservation of the functional connection between these mRNP biogenesis factors and genome integrity that had not been anticipated.
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molecular evidence that the eukaryotic tho trex complex is required for efficient Transcription Elongation
Journal of Biological Chemistry, 2003Co-Authors: Ana G Rondon, Sonia Jimeno, Maria L Garciarubio, Andres AguileraAbstract:Abstract THO/TREX is a conserved eukaryotic complex formed by the core THO complex plus proteins involved in mRNA metabolism and export such as Sub2 and Yra1. Mutations in any of the THO/TREX structural genes cause pleiotropic phenotypes such as Transcription impairment, increased Transcription-associated recombination, and mRNA export defects. To assay the relevance of THO/TREX complex in Transcription, we performed in vitro Transcription Elongation assays in mutant cell extracts using supercoiled DNA templates containing two G-less cassettes. With these assays, we demonstrate that hpr1Δ, tho2Δ, and mft1Δ mutants of the THO complex and sub2 mutants show significant reductions in the efficiency of Transcription Elongation. The mRNA expression defect of hpr1Δ mutants was not due to an increase in mRNA decay, as determined by mRNA half-life measurements and mRNA time course accumulation experiments in the absence of Rrp6p exoribonuclease. This work demonstrates that THO and Sub2 are required for efficient Transcription Elongation, providing further evidence for the coupling between Transcription and mRNA metabolism and export.
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coTranscriptionally formed dna rna hybrids mediate Transcription Elongation impairment and Transcription associated recombination
Molecular Cell, 2003Co-Authors: Pablo Huertas, Andres AguileraAbstract:Abstract Genetic instability, a phenomenon relevant for developmentally regulated processes, cancer, and inherited disorders, can be induced by Transcription. However, the mechanisms of Transcription-associated genetic instability are not yet understood. Analysis of S. cerevisiae mutants of THO/TREX, a conserved eukaryotic protein complex functioning at the interface of Transcription and mRNA metabolism, has provided evidence that Transcription Elongation impairment can cause hyperrecombination. Here we show, using hpr1Δ mutants, that the nascent mRNA can diminish Transcription Elongation efficiency and promote recombination. If during Transcription the nascent mRNA is self-cleaved by a hammerhead ribozyme, the Transcription-defect and hyperrecombination phenotypes of hpr1Δ cells are suppressed. Abolishment of hyperrecombination by overexpression of RNase H1 and molecular detection of DNA:RNA hybrids indicate that these are formed coTranscriptionally in hpr1Δ cells. These data support a model to explain the connection between recombination, Transcription, and mRNA metabolism and provide a new perspective to understanding Transcription-associated recombination.
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a protein complex containing tho2 hpr1 mft1 and a novel protein thp2 connects Transcription Elongation with mitotic recombination in saccharomyces cerevisiae
The EMBO Journal, 2000Co-Authors: Sebastian Chavez, Ana G Rondon, Traude H Beilharz, Hediye Erdjumentbromage, Paul Tempst, Jesper Q Svejstrup, Trevor Lithgow, Andres AguileraAbstract:Transcription‐induced recombination has been reported in all organisms from bacteria to mammals. We have shown previously that the yeast genes HPR1 and THO2 may be keys to the understanding of Transcription‐associated recombination, as they both affect Transcription Elongation and hyper‐recombination in a concerted manner. Using a yeast strain that has the wild‐type THO2 gene replaced by one encoding a His 6 ‐HA‐tagged version, we have isolated an oligomeric complex containing four proteins: Tho2, Hpr1, Mft1 and a novel protein that we have named Thp2. We have reciprocally identified a complex containing Hpr1, Tho2 and Mft1 using anti‐Mft1 antibodies in immunoprecipitation experiments. The protein complex is mainly nuclear; therefore, Tho2 and Hpr1 are physically associated. Like hpr1Δ and tho2Δ cells, mft1Δ and thp2Δ cells show mitotic hyper‐ recombination and impaired Transcription Elongation, in particular, through the bacterial lacZ sequence. Hyper‐recombination conferred by mft1Δ and thp2Δ is only observed in DNA regions under Transcription conditions. We propose that this protein complex acts as a functional unit connecting Transcription Elongation with the incidence of mitotic recombination.
Xiaoying Bai - One of the best experts on this subject based on the ideXlab platform.
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tif1γ controls erythroid cell fate by regulating Transcription Elongation
Cell, 2010Co-Authors: Xiaoying Bai, Jonghwan Kim, Zhongan Yang, Michael J Jurynec, Thomas E Akie, J A Lee, Jocelyn LeblancAbstract:Summary Recent genome-wide studies have demonstrated that pausing of RNA polymerase II (Pol II) occurred on many vertebrate genes. By genetic studies in the zebrafish tif1γ mutant moonshine we found that loss of function of Pol II-associated factors PAF or DSIF rescued erythroid gene Transcription in tif1γ -deficient animals. Biochemical analysis established physical interactions among TIF1γ, the blood-specific SCL Transcription complex, and the positive Elongation factors p-TEFb and FACT. Chromatin immunoprecipitation assays in human CD34 + cells supported a TIF1γ-dependent recruitment of positive Elongation factors to erythroid genes to promote Transcription Elongation by counteracting Pol II pausing. Our study establishes a mechanism for regulating tissue cell fate and differentiation through Transcription Elongation.
Tina Lenasi - One of the best experts on this subject based on the ideXlab platform.
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cap binding protein complex links pre mrna capping to Transcription Elongation and alternative splicing through positive Transcription Elongation factor b p tefb
Journal of Biological Chemistry, 2011Co-Authors: Tina Lenasi, Matija B Peterlin, Matjaz BarboricAbstract:Promoter-proximal pausing of RNAPII coincides with the formation of the cap structure at the 5′ end of pre-mRNA, which is bound by the cap-binding protein complex (CBC). Although the positive Transcription Elongation factor b (P-TEFb) stimulates the release of RNAPII from pausing and promotes Transcription Elongation and alternative splicing by phosphorylating the RNAPII C-terminal domain at Ser2 (S2-P RNAPII), it is unknown whether CBC facilitates these events. In this study, we report that CBC interacts with P-TEFb and Transcriptionally engaged RNAPII and is globally required for optimal levels of S2-P RNAPII. Quantitative nascent RNA immunoprecipitation and ChIP experiments reveal that depletion of CBC attenuates HIV-1 Tat transactivation and impedes Transcription Elongation of investigated CBC-dependent endogenous genes by decreasing the levels of P-TEFb and S2-P RNAPII, leading to accumulation of RNAPII in the body of these genes. Finally, CBC is essential for the promotion of alternative splicing through facilitating P-TEFb, S2-P RNAPII, and splicing factor 2/alternative splicing factor occupancy at a splicing minigene. These findings disclose a vital role of CBC in connecting pre-mRNA capping to Transcription Elongation and alternative splicing via P-TEFb.
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cap binding protein complex links pre mrna capping to Transcription Elongation and alternative splicing through
2011Co-Authors: Tina Lenasi, Matija B Peterlin, Matjaz BarboricAbstract:Promoter-proximal pausing of RNAPII coincides with theformationofthecapstructureatthe5 endofpre-mRNA,whichis bound by the cap-binding protein complex (CBC). Althoughthe positive Transcription Elongation factor b (P-TEFb) stimu-lates the release of RNAPII from pausing and promotes tran-scription Elongation and alternative splicing by phosphory-latingtheRNAPIIC-terminaldomainatSer2 (S2-PRNAPII),itisunknownwhetherCBCfacilitatestheseevents.Inthisstudy,wereport that CBC interacts with P-TEFb and Transcriptionallyengaged RNAPII and is globally required for optimal levels ofS2-P RNAPII. Quantitative nascent RNA immunoprecipitationand ChIP experiments reveal that depletion of CBC attenuatesHIV-1 Tat transactivation and impedes Transcription elonga-tion of investigated CBC-dependent endogenous genes bydecreasing the levels of P-TEFb and S2-P RNAPII, leading toaccumulation of RNAPII in the body of these genes. Finally,CBC is essential for the promotion of alternative splicingthrough facilitating P-TEFb, S2-P RNAPII, and splicing factor2/alternative splicing factor occupancy at a splicing minigene.These findings disclose a vital role of CBC in connectingpre-mRNA capping to Transcription Elongation and alternativesplicing via P-TEFb.
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7sk snrnp p tefb couples Transcription Elongation with alternative splicing and is essential for vertebrate development
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Matjaz Barboric, Tina Lenasi, Hui Chen, Eric B Johansen, Su Guo, Matija B PeterlinAbstract:Eukaryotic gene expression is commonly controlled at the level of RNA polymerase II (RNAPII) pausing subsequent to Transcription initiation. Transcription Elongation is stimulated by the positive Transcription Elongation factor b (P-TEFb) kinase, which is suppressed within the 7SK small nuclear ribonucleoprotein (7SK snRNP). However, the biogenesis and functional significance of 7SK snRNP remain poorly understood. Here, we report that LARP7, BCDIN3, and the noncoding 7SK small nuclear RNA (7SK) are vital for the formation and stability of a cell stress-resistant core 7SK snRNP. Our functional studies demonstrate that 7SK snRNP is not only critical for controlling Transcription Elongation, but also for regulating alternative splicing of pre-mRNAs. Using a transient expression splicing assay, we find that 7SK snRNP disintegration promotes inclusion of an alternative exon via the increased occupancy of P-TEFb, Ser2-phosphorylated (Ser2-P) RNAPII, and the splicing factor SF2/ASF at the minigene. Importantly, knockdown of larp7 or bcdin3 orthologues in zebrafish embryos destabilizes 7SK and causes severe developmental defects and aberrant splicing of analyzed transcripts. These findings reveal a key role for P-TEFb in coupling Transcription Elongation with alternative splicing, and suggest that maintaining core 7SK snRNP is essential for vertebrate development.
