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CDK9 keeps RNA polymerase II on track. Cell Mol Life Sci 2021; 78:5543-5567. [PMID: 34146121 PMCID: PMC8257543 DOI: 10.1007/s00018-021-03878-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/26/2021] [Accepted: 06/08/2021] [Indexed: 12/30/2022]
Abstract
Cyclin-dependent kinase 9 (CDK9), the kinase component of positive transcription elongation factor b (P-TEFb), is essential for transcription of most protein-coding genes by RNA polymerase II (RNAPII). By releasing promoter-proximally paused RNAPII into gene bodies, CDK9 controls the entry of RNAPII into productive elongation and is, therefore, critical for efficient synthesis of full-length messenger (m)RNAs. In recent years, new players involved in P-TEFb-dependent processes have been identified and an important function of CDK9 in coordinating elongation with transcription initiation and termination has been unveiled. As the regulatory functions of CDK9 in gene expression continue to expand, a number of human pathologies, including cancers, have been associated with aberrant CDK9 activity, underscoring the need to properly regulate CDK9. Here, I provide an overview of CDK9 function and regulation, with an emphasis on CDK9 dysregulation in human diseases.
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Sangermano F, Delicato A, Calabrò V. Y box binding protein 1 (YB-1) oncoprotein at the hub of DNA proliferation, damage and cancer progression. Biochimie 2020; 179:205-216. [PMID: 33058958 DOI: 10.1016/j.biochi.2020.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/15/2022]
Abstract
The Y Box binding protein 1 (YB-1) belongs to the highly conserved Cold Shock Domain protein family and is a major component of messenger ribonucleoprotein particles (mRNPs) in various organisms and cells. Cold Shock proteins are multifunctional nucleic acids binding proteins involved in a variety of cellular functions. Biological activities of YB-1 range from the regulation of transcription, splicing and translation, to the orchestration of exosomal RNA content. The role of YB-1 in malignant cell transformation and fate transition is the subject of intensive investigation. Besides, emerging evidence indicates that YB-1 participates in several DNA damage repair pathways as a non-canonical DNA repair factor thus pointing out that the protein can allow cancer cells to evade conventional anticancer therapies and avoid cell death. Here, we will attempt to collect and summarize the current knowledge on this subject and provide the basis for further lines of inquiry.
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Affiliation(s)
- Felicia Sangermano
- Dipartimento di Biologia, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Napoli, Italy.
| | - Antonella Delicato
- Dipartimento di Biologia, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Viola Calabrò
- Dipartimento di Biologia, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Napoli, Italy
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3
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Burger K, Ketley RF, Gullerova M. Beyond the Trinity of ATM, ATR, and DNA-PK: Multiple Kinases Shape the DNA Damage Response in Concert With RNA Metabolism. Front Mol Biosci 2019; 6:61. [PMID: 31428617 PMCID: PMC6688092 DOI: 10.3389/fmolb.2019.00061] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/11/2019] [Indexed: 12/22/2022] Open
Abstract
Our genome is constantly exposed to endogenous and exogenous sources of DNA damage resulting in various alterations of the genetic code. DNA double-strand breaks (DSBs) are considered one of the most cytotoxic lesions. Several types of repair pathways act to repair DNA damage and maintain genome stability. In the canonical DNA damage response (DDR) DSBs are recognized by the sensing kinases Ataxia-telangiectasia mutated (ATM), Ataxia-telangiectasia and Rad3-related (ATR), and DNA-dependent protein kinase (DNA-PK), which initiate a cascade of kinase-dependent amplification steps known as DSB signaling. Recent evidence suggests that efficient recognition and repair of DSBs relies on the transcription and processing of non-coding (nc)RNA molecules by RNA polymerase II (RNAPII) and the RNA interference (RNAi) factors Drosha and Dicer. Multiple kinases influence the phosphorylation status of both the RNAPII carboxy-terminal domain (CTD) and Dicer in order to regulate RNA-dependent DSBs repair. The importance of kinase signaling and RNA processing in the DDR is highlighted by the regulation of p53-binding protein (53BP1), a key regulator of DSB repair pathway choice between homologous recombination (HR) and non-homologous end joining (NHEJ). Additionally, emerging evidence suggests that RNA metabolic enzymes also play a role in the repair of other types of DNA damage, including the DDR to ultraviolet radiation (UVR). RNAi factors are also substrates for mitogen-activated protein kinase (MAPK) signaling and mediate the turnover of ncRNA during nucleotide excision repair (NER) in response to UVR. Here, we review kinase-dependent phosphorylation events on RNAPII, Drosha and Dicer, and 53BP1 that modulate the key steps of the DDR to DSBs and UVR, suggesting an intimate link between the DDR and RNA metabolism.
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Affiliation(s)
| | | | - Monika Gullerova
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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4
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Chi B, O'Connell JD, Iocolano AD, Coady JA, Yu Y, Gangopadhyay J, Gygi SP, Reed R. The neurodegenerative diseases ALS and SMA are linked at the molecular level via the ASC-1 complex. Nucleic Acids Res 2019; 46:11939-11951. [PMID: 30398641 PMCID: PMC6294556 DOI: 10.1093/nar/gky1093] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/19/2018] [Indexed: 12/12/2022] Open
Abstract
Understanding the molecular pathways disrupted in motor neuron diseases is urgently needed. Here, we employed CRISPR knockout (KO) to investigate the functions of four ALS-causative RNA/DNA binding proteins (FUS, EWSR1, TAF15 and MATR3) within the RNAP II/U1 snRNP machinery. We found that each of these structurally related proteins has distinct roles with FUS KO resulting in loss of U1 snRNP and the SMN complex, EWSR1 KO causing dissociation of the tRNA ligase complex, and TAF15 KO resulting in loss of transcription factors P-TEFb and TFIIF. However, all four ALS-causative proteins are required for association of the ASC-1 transcriptional co-activator complex with the RNAP II/U1 snRNP machinery. Remarkably, mutations in the ASC-1 complex are known to cause a severe form of Spinal Muscular Atrophy (SMA), and we show that an SMA-causative mutation in an ASC-1 component or an ALS-causative mutation in FUS disrupts association between the ASC-1 complex and the RNAP II/U1 snRNP machinery. We conclude that ALS and SMA are more intimately tied to one another than previously thought, being linked via the ASC-1 complex.
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Affiliation(s)
- Binkai Chi
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Jeremy D O'Connell
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Alexander D Iocolano
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Jordan A Coady
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Yong Yu
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Jaya Gangopadhyay
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
| | - Robin Reed
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave. Boston MA 02115, USA
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5
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A novel member of Prame family, Gm12794c, counteracts retinoic acid differentiation through the methyltransferase activity of PRC2. Cell Death Differ 2019; 27:345-362. [PMID: 31186534 DOI: 10.1038/s41418-019-0359-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/11/2019] [Accepted: 04/03/2019] [Indexed: 02/06/2023] Open
Abstract
Embryonic stem cells (ESCs) fluctuate among different levels of pluripotency defined as metastates. Sporadically, metastable cellular populations convert to a highly pluripotent metastate that resembles the preimplantation two-cell embryos stage (defined as 2C stage) in terms of transcriptome, DNA methylation, and chromatin structure. Recently, we found that the retinoic acid (RA) signaling leads to a robust increase of cells specifically expressing 2C genes, such as members of the Prame family. Here, we show that Gm12794c, one of the most highly upregulated Prame members, and previously identified as a key player for the maintenance of pluripotency, has a functional role in conferring ESCs resistance to RA signaling. In particular, RA-dependent expression of Gm12794c induces a ground state-like metastate, as evaluated by activation of 2C-specific genes, global DNA hypomethylation and rearrangement of chromatin similar to that observed in naive totipotent preimplantation epiblast cells and 2C-like cells. Mechanistically, we demonstrated that Gm12794c inhibits Cdkn1A gene expression through the polycomb repressive complex 2 (PRC2) histone methyltransferase activity. Collectively, our data highlight a molecular mechanism employed by ESCs to counteract retinoic acid differentiation stimuli and contribute to shed light on the molecular mechanisms at grounds of ESCs naive pluripotency-state maintenance.
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Ambrosio S, Di Palo G, Napolitano G, Amente S, Dellino GI, Faretta M, Pelicci PG, Lania L, Majello B. Cell cycle-dependent resolution of DNA double-strand breaks. Oncotarget 2016; 7:4949-60. [PMID: 26700820 PMCID: PMC4826256 DOI: 10.18632/oncotarget.6644] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 11/27/2015] [Indexed: 01/17/2023] Open
Abstract
DNA double strand breaks (DSBs) elicit prompt activation of DNA damage response (DDR), which arrests cell-cycle either in G1/S or G2/M in order to avoid entering S and M phase with damaged DNAs. Since mammalian tissues contain both proliferating and quiescent cells, there might be fundamental difference in DDR between proliferating and quiescent cells (or G0-arrested). To investigate these differences, we studied recruitment of DSB repair factors and resolution of DNA lesions induced at site-specific DSBs in asynchronously proliferating, G0-, or G1-arrested cells. Strikingly, DSBs occurring in G0 quiescent cells are not repaired and maintain a sustained activation of the p53-pathway. Conversely, re-entry into cell cycle of damaged G0-arrested cells, occurs with a delayed clearance of DNA repair factors initially recruited to DSBs, indicating an inefficient repair when compared to DSBs induced in asynchronously proliferating or G1-synchronized cells. Moreover, we found that initial recognition of DSBs and assembly of DSB factors is largely similar in asynchronously proliferating, G0-, or G1-synchronized cells. Our study thereby demonstrates that repair and resolution of DSBs is strongly dependent on the cell-cycle state.
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Affiliation(s)
- Susanna Ambrosio
- Department of Biology, University of Naples 'Federico II', Naples, Italy
| | - Giacomo Di Palo
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy
| | | | - Stefano Amente
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy
| | - Gaetano Ivan Dellino
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.,Department of Oncology and Haemato-Oncology, University of Milan, Milan, Italy
| | - Mario Faretta
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.,Department of Oncology and Haemato-Oncology, University of Milan, Milan, Italy
| | - Luigi Lania
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy
| | - Barbara Majello
- Department of Biology, University of Naples 'Federico II', Naples, Italy
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Al-Anee RS, Sulaiman GM, Al-Sammarrae KW, Napolitano G, Bagnati R, Lania L, Passoni A, Majello B. Chemical characterization, antioxidant and cytotoxic activities of the methanolic extract of Hymenocrater longiflorus grown in Iraq. ACTA ACUST UNITED AC 2015; 70:227-35. [DOI: 10.1515/znc-2015-4145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 07/06/2015] [Indexed: 01/20/2023]
Abstract
Abstract
Hymenocrater longiflorus was collected from northern Iraq, and the chemical composition and antioxidant and cytotoxic activities of this plant were investigated. Ten compounds detected by HPLC-ESI/MS were identified as flavonoids and phenolic acids. The free radical scavenging activity of the 70% methanol extract was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activities of the extract may be attributed to its polyphenolic composition. The cytotoxicity of the plant extract against the osteosarcoma (U2OS) cell line was assessed with the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The extract significantly reduced the viability of cells in a concentration- and time-dependent manner. Cells were arrested during the S-phase of the cell cycle, and DNA damage was revealed by antibodies against histone H2AX. The apoptotic features of cell shrinkage and decrease in cell size were also observed. Western blot analysis revealed cleavage of poly (ADP-ribose)-polymerase 1 (PARP-1), in addition to increases in the proteins p53, p21, and γ-H2AX. Collectively, our findings demonstrate that the H. longiflorus extract is highly cytotoxic to U2OS cells, most likely due to its polyphenolic composition.
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Affiliation(s)
| | - Ghassan M. Sulaiman
- Division of Biotechnology, Department of Applied Sciences, University of Technology, Baghdad, Iraq
| | | | | | - Renzo Bagnati
- Department of Environmental Health Sciences, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
| | - Luigi Lania
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Alice Passoni
- Department of Environmental Health Sciences, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
| | - Barbara Majello
- Department of Biology, University of Naples Federico II, Naples, Italy
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Ambrosio S, Amente S, Napolitano G, Di Palo G, Lania L, Majello B. MYC impairs resolution of site-specific DNA double-strand breaks repair. Mutat Res 2015; 774:6-13. [PMID: 25770827 DOI: 10.1016/j.mrfmmm.2015.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
Abstract
Although it is established that when overexpressed, the MYC family proteins can cause DNA double-stand breaks (DSBs) and genome instability, the mechanisms involved remain unclear. MYC induced genetic instability may result from increased DNA damage and/or reduced DNA repair. Here we show that when overexpressed, MYC proteins induce a sustained DNA damage response (DDR) and reduce the wave of DSBs repair. We used a cell-based DSBs system whereby, upon induction of an inducible restriction enzyme AsiSI, hundreds of site-specific DSBs are generated across the genome to investigate the role of MYC proteins on DSB. We found that high levels of MYC do not block accumulation of γH2AX at AsiSI sites, but delay its clearance, indicating an inefficient repair, while the initial recognition of DNA damage is largely unaffected. Repair of both homologous and nonhomologous repair-prone segments, characterized by high or low levels of recruited RAD51, respectively, was delayed. Collectively, these data indicate that high levels of MYC proteins delay the resolution of DNA lesions engineered to occur in cell cultures.
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Affiliation(s)
- Susanna Ambrosio
- Department of Biology, University of Naples 'Federico II', Naples, Italy
| | - Stefano Amente
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy
| | | | - Giacomo Di Palo
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy
| | - Luigi Lania
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy.
| | - Barbara Majello
- Department of Biology, University of Naples 'Federico II', Naples, Italy.
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Role of noncoding RNAs in the regulation of P-TEFb availability and enzymatic activity. BIOMED RESEARCH INTERNATIONAL 2014; 2014:643805. [PMID: 24701579 PMCID: PMC3950470 DOI: 10.1155/2014/643805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 01/13/2014] [Indexed: 11/23/2022]
Abstract
P-TEFb is a transcriptional factor that specifically regulates the elongation step of RNA polymerase II-dependent transcription and its activity strictly required for Human Immunodeficiency Virus (HIV) infection and during cardiac differentiation. P-TEFb role has emerged as a crucial regulator of transcription elongation and its activity found finely tuned in vivo at transcriptional level as well as posttranscriptionally by dynamic association with different multisubunit molecular particles. Both physiological and pathological cellular signals rapidly converge on P-TEFb regulation by modifying expression and activity of the complex to allow cells to properly respond to different stimuli. In this review we will give a panoramic view on P-TEFb regulation by noncoding RNAs in both physiological and pathological conditions.
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Napolitano G, Lania L, Majello B. RNA polymerase II CTD modifications: how many tales from a single tail. J Cell Physiol 2014; 229:538-44. [PMID: 24122273 DOI: 10.1002/jcp.24483] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/30/2013] [Indexed: 12/31/2022]
Abstract
Eukaryote's RNA polymerases II (RNAPII) have the feature to contain, at the carbossi-terminal region of their largest subunit Rpb1, a unique CTD domain. Rpb1-CTD is composed of an increasing number of repetitions of the Y1 S2 P3 T4 S5 P6 S7 heptad that goes in parallel with the developmental level of organisms. Because of its composition, the CTD domain has a huge structural plasticity; virtually all the residues can be subjected to post-translational modifications and the two prolines can either be in cis or trans conformations. In light of these features, it is reasonable to think that different specific nuances of CTD modification and interacting factors take place not only on different gene promoters but also during different stages of the transcription cycle and reasonably might have a role even if the polymerase is on or off the DNA template. Rpb1-CTD domain is involved not only in regulating transcriptional rates, but also in all co-transcriptional processes, such as pre-mRNA processing, splicing, cleavage, and export. Moreover, recent studies highlight a role of CTD in DNA replication and in maintenance of genomic stability and specific CTD-modifications have been related to different CTD functions. In this paper, we examine results from the most recent CTD-related literature and give an overview of the general function of Rpb1-CTD in transcription, transcription-related and non transcription-related processes in which it has been recently shown to be involved in.
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