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  1. Article ; Online: P-TEFb promotes cell survival upon p53 activation by suppressing intrinsic apoptosis pathway.

    Wang, Zhijia / Mačáková, Monika / Bugai, Andrii / Kuznetsov, Sergey G / Hassinen, Antti / Lenasi, Tina / Potdar, Swapnil / Friedel, Caroline C / Barborič, Matjaž

    Nucleic acids research

    2023  Volume 51, Issue 4, Page(s) 1687–1706

    Abstract: Positive transcription elongation factor b (P-TEFb) is the crucial player in RNA polymerase II (Pol II) pause release that has emerged as a promising target in cancer. Because single-agent therapy may fail to deliver durable clinical response, targeting ... ...

    Abstract Positive transcription elongation factor b (P-TEFb) is the crucial player in RNA polymerase II (Pol II) pause release that has emerged as a promising target in cancer. Because single-agent therapy may fail to deliver durable clinical response, targeting of P-TEFb shall benefit when deployed as a combination therapy. We screened a comprehensive oncology library and identified clinically relevant antimetabolites and Mouse double minute 2 homolog (MDM2) inhibitors as top compounds eliciting p53-dependent death of colorectal cancer cells in synergy with selective inhibitors of P-TEFb. While the targeting of P-TEFb augments apoptosis by anti-metabolite 5-fluorouracil, it switches the fate of cancer cells by the non-genotoxic MDM2 inhibitor Nutlin-3a from cell-cycle arrest to apoptosis. Mechanistically, the fate switching is enabled by the induction of p53-dependent pro-apoptotic genes and repression of P-TEFb-dependent pro-survival genes of the PI3K-AKT signaling cascade, which stimulates caspase 9 and intrinsic apoptosis pathway in BAX/BAK-dependent manner. Finally, combination treatments trigger apoptosis of cancer cell spheroids. Together, co-targeting of P-TEFb and suppressors of intrinsic apoptosis could become a viable strategy to eliminate cancer cells.
    MeSH term(s) Apoptosis ; Cell Line, Tumor ; Cell Survival ; Phosphatidylinositol 3-Kinases/metabolism ; Positive Transcriptional Elongation Factor B/antagonists & inhibitors ; Positive Transcriptional Elongation Factor B/metabolism ; Proto-Oncogene Proteins c-mdm2/genetics ; Tumor Suppressor Protein p53/genetics ; Humans
    Chemical Substances Phosphatidylinositol 3-Kinases (EC 2.7.1.-) ; Positive Transcriptional Elongation Factor B (EC 2.7.11.-) ; Proto-Oncogene Proteins c-mdm2 (EC 2.3.2.27) ; Tumor Suppressor Protein p53 ; MDM2 protein, human (EC 2.3.2.27)
    Language English
    Publishing date 2023-02-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkad001
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Mutual relationships between transcription and pre-mRNA processing in the synthesis of mRNA.

    Lenasi, Tina / Barboric, Matjaz

    Wiley interdisciplinary reviews. RNA

    2013  Volume 4, Issue 2, Page(s) 139–154

    Abstract: The generation of messenger RNA (mRNA) in eukaryotes is achieved by transcription from the DNA template and pre-mRNA processing reactions of capping, splicing, and polyadenylation. Although RNA polymerase II (RNAPII) catalyzes the synthesis of pre-mRNA, ... ...

    Abstract The generation of messenger RNA (mRNA) in eukaryotes is achieved by transcription from the DNA template and pre-mRNA processing reactions of capping, splicing, and polyadenylation. Although RNA polymerase II (RNAPII) catalyzes the synthesis of pre-mRNA, it also serves as a principal coordinator of the processing reactions in the course of transcription. In this review, we focus on the interplay between transcription and cotranscriptional pre-mRNA maturation events, mediated by the recruitment of RNA processing factors to differentially phosphorylated C-terminal domain of Rbp1, the largest subunit of RNAPII. Furthermore, we highlight the bidirectional nature of the interplay by discussing the impact of RNAPII kinetics on pre-mRNA processing as well as how the processing events reach back to different phases of gene transcription.
    MeSH term(s) Animals ; Humans ; RNA Precursors/genetics ; RNA Precursors/metabolism ; RNA Processing, Post-Transcriptional ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; Transcription, Genetic
    Chemical Substances RNA Precursors ; RNA, Messenger
    Language English
    Publishing date 2013-03
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2634714-3
    ISSN 1757-7012 ; 1757-7004
    ISSN (online) 1757-7012
    ISSN 1757-7004
    DOI 10.1002/wrna.1148
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: P-TEFb stimulates transcription elongation and pre-mRNA splicing through multilateral mechanisms.

    Lenasi, Tina / Barboric, Matjaz

    RNA biology

    2010  Volume 7, Issue 2, Page(s) 145–150

    Abstract: Promoter-proximal pausing of RNA polymerase II (RNAPII) across the genome has renewed our attention to the early transcriptional events that control the establishment of pausing and the release of RNAPII into a productive transcription elongation. Here, ... ...

    Abstract Promoter-proximal pausing of RNA polymerase II (RNAPII) across the genome has renewed our attention to the early transcriptional events that control the establishment of pausing and the release of RNAPII into a productive transcription elongation. Here, we review our current understanding of the transcriptional cycle by RNAPII with a particular emphasis on the mechanisms that stimulate transcription elongation and cotranscriptional pre-mRNA splicing through an essential transcriptional kinase, the positive transcription elongation factor b (P-TEFb). We illustrate that by targeting a limited set of transcription elongation factors and paused RNAPII molecule during a promoter-proximal phase of transcription, P-TEFb unleashes an extensive crosstalk between transcription apparatus, RNA processing factors and chromatin for optimal production of mRNA.
    MeSH term(s) Animals ; Positive Transcriptional Elongation Factor B/metabolism ; RNA Polymerase II/chemistry ; RNA Polymerase II/metabolism ; RNA Precursors/genetics ; RNA Splicing/genetics ; Ribonucleoproteins, Small Nuclear/metabolism ; Transcription, Genetic
    Chemical Substances RNA Precursors ; Ribonucleoproteins, Small Nuclear ; Positive Transcriptional Elongation Factor B (EC 2.7.11.-) ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2010-03-29
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ISSN 1555-8584
    ISSN (online) 1555-8584
    DOI 10.4161/rna.7.2.11057
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Kick-sTARting HIV-1 transcription elongation by 7SK snRNP deporTATion.

    Barboric, Matjaz / Lenasi, Tina

    Nature structural & molecular biology

    2010  Volume 17, Issue 8, Page(s) 928–930

    Abstract: The HIV-1 Tat protein promotes viral transcription elongation by recruiting P-TEFb to RNA element TAR on the viral mRNA. Recent work from D'Orso and Frankel uncovers unexpected aspects of this process. ...

    Abstract The HIV-1 Tat protein promotes viral transcription elongation by recruiting P-TEFb to RNA element TAR on the viral mRNA. Recent work from D'Orso and Frankel uncovers unexpected aspects of this process.
    MeSH term(s) Gene Expression Regulation, Viral ; HIV Long Terminal Repeat/genetics ; HIV-1/genetics ; Models, Genetic ; Positive Transcriptional Elongation Factor B/metabolism ; RNA Polymerase II/metabolism ; Ribonucleoproteins, Small Nuclear/metabolism ; Transcription, Genetic ; Transcriptional Activation/genetics ; tat Gene Products, Human Immunodeficiency Virus/genetics ; tat Gene Products, Human Immunodeficiency Virus/metabolism
    Chemical Substances Ribonucleoproteins, Small Nuclear ; tat Gene Products, Human Immunodeficiency Virus ; Positive Transcriptional Elongation Factor B (EC 2.7.11.-) ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2010-08-04
    Publishing country United States
    Document type Comment ; News
    ZDB-ID 2126708-X
    ISSN 1545-9985 ; 1545-9993
    ISSN (online) 1545-9985
    ISSN 1545-9993
    DOI 10.1038/nsmb0810-928
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: P-TEFb stimulates transcription elongation and pre-mRNA splicing through multilateral mechanisms

    Lenasi, Tina / Barboric, Matjaz

    RNA biology. 2010 Mar. 1, v. 7, no. 2

    2010  

    Abstract: Promoter-proximal pausing of RNA polymerase II (RNAPII) across the genome has renewed our attention to the early transcriptional events that control the establishment of pausing and the release of RNAPII into a productive transcription elongation. Here, ... ...

    Abstract Promoter-proximal pausing of RNA polymerase II (RNAPII) across the genome has renewed our attention to the early transcriptional events that control the establishment of pausing and the release of RNAPII into a productive transcription elongation. Here, we review our current understanding of the transcriptional cycle by RNAPII with a particular emphasis on the mechanisms that stimulate transcription elongation and cotranscriptional pre-mRNA splicing through an essential transcriptional kinase, the positive transcription elongation factor b (P-TEFb). We illustrate that by targeting a limited set of transcription elongation factors and paused RNAPII molecule during an early phase of transcription, P-TEFb unleashes an extensive crosstalk between transcription apparatus, RNA processing factors and chromatin for optimal production of mRNA.
    Keywords DNA-directed RNA polymerase ; chromatin ; genome ; transcription (genetics) ; transcriptional elongation factors
    Language English
    Dates of publication 2010-0301
    Size p. 145-150.
    Publishing place Taylor & Francis
    Document type Article
    ISSN 1555-8584
    DOI 10.4161/rna.7.2.11057
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: Cap-binding protein complex links pre-mRNA capping to transcription elongation and alternative splicing through positive transcription elongation factor b (P-TEFb).

    Lenasi, Tina / Peterlin, B Matija / Barboric, Matjaz

    The Journal of biological chemistry

    2011  Volume 286, Issue 26, Page(s) 22758–22768

    Abstract: 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 ... ...

    Abstract 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.
    MeSH term(s) Alternative Splicing/physiology ; HeLa Cells ; Humans ; Positive Transcriptional Elongation Factor B/genetics ; Positive Transcriptional Elongation Factor B/metabolism ; RNA Cap-Binding Proteins/genetics ; RNA Cap-Binding Proteins/metabolism ; RNA Polymerase II/genetics ; RNA Polymerase II/metabolism ; RNA Precursors/biosynthesis ; RNA Precursors/genetics ; Transcription, Genetic/physiology
    Chemical Substances RNA Cap-Binding Proteins ; RNA Precursors ; Positive Transcriptional Elongation Factor B (EC 2.7.11.-) ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2011-05-02
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.M111.235077
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: P-TEFb Activation by RBM7 Shapes a Pro-survival Transcriptional Response to Genotoxic Stress.

    Bugai, Andrii / Quaresma, Alexandre J C / Friedel, Caroline C / Lenasi, Tina / Düster, Robert / Sibley, Christopher R / Fujinaga, Koh / Kukanja, Petra / Hennig, Thomas / Blasius, Melanie / Geyer, Matthias / Ule, Jernej / Dölken, Lars / Barborič, Matjaž

    Molecular cell

    2019  Volume 74, Issue 2, Page(s) 254–267.e10

    Abstract: DNA damage response (DDR) involves dramatic transcriptional alterations, the mechanisms of which remain ill defined. Here, we show that following genotoxic stress, the RNA-binding motif protein 7 (RBM7) stimulates RNA polymerase II (Pol II) transcription ...

    Abstract DNA damage response (DDR) involves dramatic transcriptional alterations, the mechanisms of which remain ill defined. Here, we show that following genotoxic stress, the RNA-binding motif protein 7 (RBM7) stimulates RNA polymerase II (Pol II) transcription and promotes cell viability by activating the positive transcription elongation factor b (P-TEFb) via its release from the inhibitory 7SK small nuclear ribonucleoprotein (7SK snRNP). This is mediated by activation of p38
    MeSH term(s) Apoptosis/genetics ; Cell Survival/genetics ; DNA Damage/genetics ; HEK293 Cells ; Humans ; Positive Transcriptional Elongation Factor B/genetics ; RNA Polymerase II/genetics ; RNA, Long Noncoding/genetics ; RNA-Binding Proteins/genetics ; Ribonucleoproteins, Small Nuclear/genetics ; Transcription, Genetic ; p38 Mitogen-Activated Protein Kinases/genetics
    Chemical Substances RBM7 protein, human ; RNA, Long Noncoding ; RNA-Binding Proteins ; Ribonucleoproteins, Small Nuclear ; long non-coding RNA 7SK, human ; Positive Transcriptional Elongation Factor B (EC 2.7.11.-) ; p38 Mitogen-Activated Protein Kinases (EC 2.7.11.24) ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2019-02-26
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1415236-8
    ISSN 1097-4164 ; 1097-2765
    ISSN (online) 1097-4164
    ISSN 1097-2765
    DOI 10.1016/j.molcel.2019.01.033
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: HIV latency: present knowledge, future directions.

    Contreras, Xavier / Lenasi, Tina / Peterlin, B Matija

    Future virology

    2009  Volume 1, Issue 6, Page(s) 733–745

    Abstract: Current therapies do not eradicate HIV from infected patients. Indeed, HIV hides in a latent form insensitive to these therapies. Thus, one priority is to purge these latent reservoirs. But what mechanisms are responsible for latency and what are the ... ...

    Abstract Current therapies do not eradicate HIV from infected patients. Indeed, HIV hides in a latent form insensitive to these therapies. Thus, one priority is to purge these latent reservoirs. But what mechanisms are responsible for latency and what are the reservoirs of latently infected cells? The present knowledge in terms of HIV latency is still incomplete and current therapeutic strategies fail to eradicate completely latently infected cells. What could the future bring?
    Language English
    Publishing date 2009-05-18
    Publishing country England
    Document type Journal Article
    ISSN 1746-0794
    ISSN 1746-0794
    DOI 10.2217/17460794.1.6.733
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Transcriptional interference antagonizes proviral gene expression to promote HIV latency.

    Lenasi, Tina / Contreras, Xavier / Peterlin, B Matija

    Cell host & microbe

    2008  Volume 4, Issue 2, Page(s) 123–133

    Abstract: Eradication of the latent HIV reservoir remains a major barrier to curing AIDS. However, the mechanisms that direct viral persistence in the host are not well understood. Studying a model system of postintegration latency, we found that viral integration ...

    Abstract Eradication of the latent HIV reservoir remains a major barrier to curing AIDS. However, the mechanisms that direct viral persistence in the host are not well understood. Studying a model system of postintegration latency, we found that viral integration into the actively transcribed host genes led to transcriptional interference (TI) caused by the elongating RNA polymerase II (RNAPII) transcribing through the viral promoter. The resulting physical exclusion of preinitiation complex formation on the 5' long terminal repeat (LTR) promoted the silencing of HIV transcription. This block could be counteracted by inhibiting the upstream transcription or cooperatively activating viral transcription initiation and elongation. Importantly, PCR-based analysis, which detects host transcription through the 5'LTR independently of the viral integration site, revealed substantial levels of this transcription in HIV-infected primary CD4(+) T cells. Collectively, our findings suggest that TI contributes significantly to HIV latency and should be considered when attempting to purge the latent reservoir.
    MeSH term(s) CD4-Positive T-Lymphocytes/virology ; Gene Expression Regulation, Viral ; Genome, Viral ; Glycoproteins/genetics ; Glycoproteins/metabolism ; HIV/genetics ; HIV/physiology ; HIV Infections/genetics ; HIV Infections/virology ; HIV Long Terminal Repeat ; Host-Pathogen Interactions ; Humans ; Jurkat Cells ; Proviruses/genetics ; Proviruses/physiology ; RNA Polymerase II/genetics ; RNA Polymerase II/metabolism ; Transcription, Genetic ; Virus Latency
    Chemical Substances Glycoproteins ; tissue-factor-pathway inhibitor 2 ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2008-07-22
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2278004-X
    ISSN 1934-6069 ; 1931-3128
    ISSN (online) 1934-6069
    ISSN 1931-3128
    DOI 10.1016/j.chom.2008.05.016
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Distal regulation of alternative splicing by splicing enhancer in equine beta-casein intron 1.

    Lenasi, Tina / Peterlin, B Matija / Dovc, Peter

    RNA (New York, N.Y.)

    2006  Volume 12, Issue 3, Page(s) 498–507

    Abstract: The complexity of cotranscriptional splicing is reflected in the coordinated interplay between various cis-elements and transacting factors. In this report, we demonstrated that a cis-element in intron 1 of the equine beta-casein gene (intronic splicing ... ...

    Abstract The complexity of cotranscriptional splicing is reflected in the coordinated interplay between various cis-elements and transacting factors. In this report, we demonstrated that a cis-element in intron 1 of the equine beta-casein gene (intronic splicing enhancer 1, ISE1) increases the inclusion of all weak exons in its pre-mRNA. The ISE1 also functioned on a hybrid transcript, which was transcribed from the alpha-globin promoter, where it increased the inclusion of the human fibronectin EDA exon and the beta-casein exon 5. The region of ISE1 necessary for its function included the same sequence as is found in some exonic splicing enhancers. Since the ISE1 influenced the splicing of the entire transcript from intron 1, we propose a model for the cotranscriptional splicing of beta-casein mRNA, where the 5' end of the growing transcript remains associated with the C-terminal domain of RNA polymerase II. Thus, the ISE1 remains in close proximity to the mRNA exit groove throughout transcription and influences all weak exons as soon as they are copied.
    MeSH term(s) Alternative Splicing ; Animals ; Base Sequence ; Caseins/genetics ; DNA/genetics ; Enhancer Elements, Genetic ; Exons ; Female ; Globins/genetics ; Horses/genetics ; Horses/metabolism ; Humans ; Introns ; Molecular Sequence Data ; Mutagenesis ; Polymorphism, Genetic ; RNA Precursors/genetics ; RNA Precursors/metabolism
    Chemical Substances Caseins ; RNA Precursors ; Globins (9004-22-2) ; DNA (9007-49-2)
    Language English
    Publishing date 2006-01-23
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1241540-6
    ISSN 1355-8382
    ISSN 1355-8382
    DOI 10.1261/rna.7261206
    Database MEDical Literature Analysis and Retrieval System OnLINE

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