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Kyheröinen S, Prajapati B, Sokolova M, Schmitz M, Viita T, Geyer M, Vartiainen MK. Actin associates with actively elongating genes and binds directly to the Cdk9 subunit of P-TEFb. J Biol Chem 2024; 300:105698. [PMID: 38301887 PMCID: PMC10891344 DOI: 10.1016/j.jbc.2024.105698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/08/2024] [Accepted: 01/21/2024] [Indexed: 02/03/2024] Open
Abstract
Nuclear actin has been demonstrated to be essential for optimal transcription, but the molecular mechanisms and direct binding partner for actin in the RNA polymerase complex have remained unknown. By using purified proteins in a variety of biochemical assays, we demonstrate a direct and specific interaction between monomeric actin and Cdk9, the kinase subunit of the positive transcription elongation factor b required for RNA polymerase II pause-release. This interaction efficiently prevents actin polymerization, is not dependent on kinase activity of Cdk9, and is not involved with releasing positive transcription elongation factor b from its inhibitor 7SK snRNP complex. Supporting the specific role for actin in the elongation phase of transcription, chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) reveals that actin interacts with genes only upon their active transcription elongation. This study therefore provides novel insights into the mechanisms by which actin facilitates the transcription process.
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Affiliation(s)
- Salla Kyheröinen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Bina Prajapati
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Maria Sokolova
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | | | - Tiina Viita
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Maria K Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
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Xue Q, Zhang Q, Guo Z, Wu L, Chen Y, Chen Z, Yang K, Cao J. Therapeutic Hypothermia Inhibits Hypoxia-Induced Cardiomyocyte Apoptosis Via the MiR-483-3p/ Cdk9 Axis. J Am Heart Assoc 2023; 12:e026160. [PMID: 36789845 PMCID: PMC10111479 DOI: 10.1161/jaha.122.026160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Background Therapeutic hypothermia has a beneficial effect on cardiac function after acute myocardial infarction, but the exact mechanism is still unclear. Recent research has suggested that microRNAs participate in acute myocardial infarction to regulate cardiomyocyte survival. This study aimed to explore the ability of hypothermia-regulated microRNA-483-3p (miR-483-3p) to inhibit hypoxia-induced myocardial infarction. Methods and Results Primary cardiomyocytes were cultured under hypoxia at 32 °C to mimic therapeutic hypothermia, and the differentially expressed microRNAs were determined by RNA sequencing. Therapeutic hypothermia recovered hypoxia-induced increases in apoptosis, decreases in ATP levels, and decreases in miR-483-3p expression. Overexpression of miR-483-3p exhibited effects similar to those of therapeutic hypothermia on hypoxia in the treatment of cardiomyocytes to associate with maintaining the mitochondrial membrane potential, and cyclin-dependent kinase 9 (Cdk9) was identified as a target gene with downregulated expression by miR-483-3p. Knockdown of Cdk9 also promoted cardiac survival, ATP production, and mitochondrial membrane potential stability under hypoxia. In vivo, the expression of miR-483-3p and Cdk9 was tested in the cardiac tissue of the mice with acute myocardial infarction, and the expression of miR-483-3p decreased and Cdk9 increased in the region of myocardial infarction. However, miR-483-3p was overexpressed with lentivirus, which suppressed apoptosis, infarct size (miR-483-3p, 22.00±4.04% versus negative control, 28.57±5.44%, P<0.05), and Cdk9 expression to improve cardiac contractility. Conclusions MiR-483-3p antagonizes hypoxia, leading to cardiomyocyte injury by targeting Cdk9, which is a new mechanism of therapeutic hypothermia.
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Affiliation(s)
- Qiqi Xue
- Department of Geriatrics Ruijin Hospital, Shanghai Jiaotong University School of Medicine Shanghai China
| | - Qianru Zhang
- Department of Cardiology Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai China
| | - Zhenzhen Guo
- Department of Cardiovascular Medicine Ruijin Hospital, Shanghai Jiaotong University School of Medicine Shanghai China
| | - Liping Wu
- Department of Cardiac Imaging Center The First Affiliated Hospital, Auhui Medical University Hefei China
| | - Yafen Chen
- Shanghai Institute of Cardiovascular Diseases Zhongshan Hospital, Fudan University Shanghai China
| | - Zhongli Chen
- State Key Laboratory of Cardiovascular Disease Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing China
| | - Ke Yang
- Department of Cardiovascular Medicine Ruijin Hospital, Shanghai Jiaotong University School of Medicine Shanghai China
| | - Jiumei Cao
- Department of Geriatrics Ruijin Hospital, Shanghai Jiaotong University School of Medicine Shanghai China
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3
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Funamoto M, Sunagawa Y, Gempei M, Shimizu K, Katanasaka Y, Shimizu S, Hamabe-Horiike T, Appendino G, Minassi A, Koeberle A, Komiyama M, Mori K, Hasegawa K, Morimoto T. Pyrazole-Curcumin Suppresses Cardiomyocyte Hypertrophy by Disrupting the CDK9/CyclinT1 Complex. Pharmaceutics 2022; 14:1269. [PMID: 35745840 DOI: 10.3390/pharmaceutics14061269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 11/25/2022] Open
Abstract
The intrinsic histone acetyltransferase (HAT), p300, has an important role in the development and progression of heart failure. Curcumin (CUR), a natural p300-specific HAT inhibitor, suppresses hypertrophic responses and prevents deterioration of left-ventricular systolic function in heart-failure models. However, few structure–activity relationship studies on cardiomyocyte hypertrophy using CUR have been conducted. To evaluate if prenylated pyrazolo curcumin (PPC) and curcumin pyrazole (PyrC) can suppress cardiomyocyte hypertrophy, cultured cardiomyocytes were treated with CUR, PPC, or PyrC and then stimulated with phenylephrine (PE). PE-induced cardiomyocyte hypertrophy was inhibited by PyrC but not PPC at a lower concentration than CUR. Western blotting showed that PyrC suppressed PE-induced histone acetylation. However, an in vitro HAT assay showed that PyrC did not directly inhibit p300-HAT activity. As Cdk9 phosphorylates both RNA polymerase II and p300 and increases p300-HAT activity, the effects of CUR and PyrC on the kinase activity of Cdk9 were examined. Phosphorylation of p300 by Cdk9 was suppressed by PyrC. Immunoprecipitation-WB showed that PyrC inhibits Cdk9 binding to CyclinT1 in cultured cardiomyocytes. PyrC may prevent cardiomyocyte hypertrophic responses by indirectly suppressing both p300-HAT activity and RNA polymerase II transcription elongation activity via inhibition of Cdk9 kinase activity.
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4
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Li M, Ren C, Zhou S, He Y, Guo Y, Zhang H, Liu L, Cao Q, Wang C, Huang J, Hu Y, Bai X, Guo X, Shu W, Huo R. Integrative proteome analysis implicates aberrant RNA splicing in impaired developmental potential of aged mouse oocytes. Aging Cell 2021; 20:e13482. [PMID: 34582091 PMCID: PMC8520726 DOI: 10.1111/acel.13482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 08/18/2021] [Accepted: 09/11/2021] [Indexed: 12/24/2022] Open
Abstract
Aging has many effects on the female reproductive system, among which decreased oocyte quality and impaired embryo developmental potential are the most important factors affecting female fertility. However, the mechanisms underlying oocyte aging are not yet fully understood. Here, we selected normal reproductively aging female mice and constructed a protein expression profile of metaphase II (MII) oocytes from three age groups. A total of 187 differentially expressed (DE) proteins were identified, and bioinformatics analyses showed that these DE proteins were highly enriched in RNA splicing. Next, RNA‐seq was performed on 2‐cell embryos from these three age groups, and splicing analysis showed that a large number of splicing events and genes were discovered at this stage. Differentially spliced genes (DSGs) in the two reproductively aging groups versus the younger group were enriched in biological processes related to DNA damage repair/response. Binding motif analysis suggested that PUF60 might be one of the core splicing factors causing a decline in DNA repair capacity in the subsequent development of oocytes from reproductively aging mice, and changing the splicing pattern of its potential downstream DSG Cdk9 could partially mimic phenotypes in the reproductively aging groups. Taken together, our study suggested that the abnormal expression of splicing regulation proteins in aged MII oocytes would affect the splicing of nascent RNA after zygotic genome activation in 2‐cell embryos, leading to the production of abnormally spliced transcripts of some key genes associated with DNA damage repair/response, thus affecting the developmental potential of aged oocytes.
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Affiliation(s)
- Mingrui Li
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
- Department of Clinical Nursing, School of Nursing Nanjing Medical University Nanjing China
| | - Chao Ren
- Department of Biotechnology Beijing Institute of Radiation Medicine Beijing China
| | - Shuai Zhou
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Yuanlin He
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Yueshuai Guo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Hao Zhang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Lu Liu
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Qiqi Cao
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Congjing Wang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Jie Huang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Yue Hu
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Xue Bai
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Xuejiang Guo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
| | - Wenjie Shu
- Department of Biotechnology Beijing Institute of Radiation Medicine Beijing China
| | - Ran Huo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University Nanjing China
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5
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Fukui T, Yik JHN, Doyran B, Davis J, Haudenschild AK, Adamopoulos IE, Han L, Haudenschild DR. Bromodomain-containing-protein-4 and cyclin-dependent-kinase-9 inhibitors interact synergistically in vitro and combined treatment reduces post-traumatic osteoarthritis severity in mice. Osteoarthritis Cartilage 2021; 29:68-77. [PMID: 33164842 PMCID: PMC7785706 DOI: 10.1016/j.joca.2020.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 06/30/2020] [Accepted: 07/20/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Joint injury rapidly induces expression of primary response genes (PRGs), which activate a cascade of secondary genes that destroy joint tissues and initiate post-traumatic osteoarthritis (PTOA). Bromodomain-containing-protein-4 (Brd4) and cyclin-dependent-kinase-9 (CDK9) cooperatively control the rate-limiting step of PRG transactivation, including pro-inflammatory genes. This study investigated whether Brd4 and CDK9 inhibitors suppress inflammation and prevent PTOA development in vitro and in a mouse PTOA model. METHODS The effects of Brd4 and CDK9 inhibitors (JQ1 and Flavopiridol) on PRG and associated secondary damage were rigorously tested in different settings. Short-term effects of inflammatory stimuli (IL-1β, IL-6, TNF) on human chondrocyte PRG expression were assessed by RT-PCR and microarray after 5-h. We quantified glycosaminoglycan release from IL-1β-treated bovine cartilage explants after 3-6 days, and osteoarthritic changes in mice after ACL-rupture using RT-PCR (2-24hrs), in vivo imaging of MMP activity (24hrs), AFM-nanoindentation (3-7days), and histology (3days-4wks). RESULTS Flavopiridol and JQ1 inhibitors act synergistically, and a combination of both almost completely prevented the activation of most IL-1β-induced PRGs in vitro by microarray analysis, and prevented IL-1β-induced glycosaminoglycan release from cartilage explants. Mice given the drug combination showed reduced IL-1β and IL-6 expression, less in vivo MMP activity, and lower synovitis (1.5 vs 4.9) and OARSI scores (2.8 vs 6.0) than untreated mice with ACL-rupture. CONCLUSIONS JQ1 and Flavopiridol work synergistically to reduce injury response after joint trauma, suggesting that targeting Brd4 and/or CDK9 could be a viable strategy for PTOA prevention and treatment of early OA.
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Affiliation(s)
- Tomoaki Fukui
- Department of Orthopaedic Surgery, University of California Davis School of Medicine, 4635 Second Avenue, Sacramento, CA 95817 USA Tel:916-734-5015 Fax:916-734-5750
| | - Jasper H. N. Yik
- Department of Orthopaedic Surgery, University of California Davis School of Medicine, 4635 Second Avenue, Sacramento, CA 95817 USA Tel:916-734-5015 Fax:916-734-5750
| | - Basak Doyran
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Jack Davis
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California, Sacramento, CA, USA
| | - Anne K. Haudenschild
- Department of Biomedical Engineering, University of California Davis, Davis, CA USA
| | - Iannis E. Adamopoulos
- Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, Davis, CA, USA,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California, Sacramento, CA, USA
| | - Lin Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - Dominik R. Haudenschild
- Department of Orthopaedic Surgery, University of California Davis School of Medicine, 4635 Second Avenue, Sacramento, CA 95817 USA Tel:916-734-5015 Fax:916-734-5750
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6
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Schoenherr C, Byron A, Griffith B, Loftus A, Wills JC, Munro AF, von Kriegsheim A, Frame MC. The autophagy protein Ambra1 regulates gene expression by supporting novel transcriptional complexes. J Biol Chem 2020; 295:12045-12057. [PMID: 32616651 PMCID: PMC7443501 DOI: 10.1074/jbc.ra120.012565] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/24/2020] [Indexed: 12/13/2022] Open
Abstract
Ambra1 is considered an autophagy and trafficking protein with roles in neurogenesis and cancer cell invasion. Here, we report that Ambra1 also localizes to the nucleus of cancer cells, where it has a novel nuclear scaffolding function that controls gene expression. Using biochemical fractionation and proteomics, we found that Ambra1 binds to multiple classes of proteins in the nucleus, including nuclear pore proteins, adaptor proteins such as FAK and Akap8, chromatin-modifying proteins, and transcriptional regulators like Brg1 and Atf2. We identified biologically important genes, such as Angpt1, Tgfb2, Tgfb3, Itga8, and Itgb7, whose transcription is regulated by Ambra1-scaffolded complexes, likely by altering histone modifications and Atf2 activity. Therefore, in addition to its recognized roles in autophagy and trafficking, Ambra1 scaffolds protein complexes at chromatin, regulating transcriptional signaling in the nucleus. This novel function for Ambra1, and the specific genes impacted, may help to explain the wider role of Ambra1 in cancer cell biology.
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Affiliation(s)
- Christina Schoenherr
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Byron
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Billie Griffith
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alexander Loftus
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Jimi C Wills
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alison F Munro
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alex von Kriegsheim
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Margaret C Frame
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom.
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7
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Chen JJ, Mbogning J, Hancock MA, Majdpour D, Madhok M, Nassour H, Dallagnol JC, Pagé V, Chatenet D, Tanny JC. Spt5 Phosphorylation and the Rtf1 Plus3 Domain Promote Rtf1 Function through Distinct Mechanisms. Mol Cell Biol 2020; 40:e00150-20. [PMID: 32366382 DOI: 10.1128/MCB.00150-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 04/28/2020] [Indexed: 11/20/2022] Open
Abstract
Rtf1 is a conserved RNA polymerase II (RNAPII) elongation factor that promotes cotranscriptional histone modification, RNAPII transcript elongation, and mRNA processing. Rtf1 function requires the phosphorylation of Spt5, an essential RNAPII processivity factor. Spt5 is phosphorylated within its C-terminal domain (CTD) by cyclin-dependent kinase 9 (Cdk9), the catalytic component of positive transcription elongation factor b (P-TEFb). Rtf1 recognizes phosphorylated Spt5 (pSpt5) through its Plus3 domain. Since Spt5 is a unique target of Cdk9 and Rtf1 is the only known pSpt5-binding factor, the Plus3/pSpt5 interaction is thought to be a key Cdk9-dependent event regulating RNAPII elongation. Here, we dissect Rtf1 regulation by pSpt5 in the fission yeast Schizosaccharomyces pombe We demonstrate that the Plus3 domain of Rtf1 (Prf1 in S. pombe) and pSpt5 are functionally distinct and that they act in parallel to promote Prf1 function. This alternate Plus3 domain function involves an interface that overlaps the pSpt5-binding site and that can interact with single-stranded nucleic acid or with the polymerase-associated factor (PAF) complex in vitro We further show that the C-terminal region of Prf1, which also interacts with PAF, has a similar parallel function with pSpt5. Our results elucidate unexpected complexity underlying Cdk9-dependent pathways that regulate transcription elongation.
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8
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Hagiwara A, Ogiwara K, Sugama N, Yamashita M, Takahashi T. Inhibition of medaka ovulation by gap junction blockers due to its disrupting effect on the transcriptional process of LH-induced Mmp15 expression. Gen Comp Endocrinol 2020; 288:113373. [PMID: 31874135 DOI: 10.1016/j.ygcen.2019.113373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/11/2019] [Accepted: 12/19/2019] [Indexed: 10/25/2022]
Abstract
Using medaka, we found that in vitro follicle ovulation, but not germinal vesicle breakdown, was inhibited by three gap junction blockers, carbenoxolone, mefloquine, and flufenamic acid. The blockers specifically inhibited follicular expression of matrix metalloproteinase-15 mRNA and the protein (mmp15/Mmp15), a protease indispensable for medaka ovulation, indicating that gap junctional communication may be required for successful ovulation and mmp15/Mmp15 expression. Further experiments using carbenoxolone as the representative of the gap junction blockers showed that expression of nuclear progestin receptor (Pgr), a transcription factor required for mmp15 expression, was not affected by carbenoxolone treatment, but the formation of phosphorylated Pgr was considerably suppressed. Carbenoxolone treatment caused a decrease in the Pgr binding to the promoter region of mmp15. mRNA expression of cyclin-dependent protein kinase-9 (cdk9) and cyclin I (ccni), whose translation products are demonstrated to be involved in Pgr phosphorylation in the medaka ovulating follicles, was suppressed by carbenoxolone treatment. Transcripts of connexin 34.5 (cx34.5) and connexin 35.4 (cx35.4) were dominantly expressed in the follicle cells of ovulating follicles. The results indicate that gap junctional communication plays an important role in medaka ovulation.
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Affiliation(s)
- Akane Hagiwara
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Katsueki Ogiwara
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
| | - Natsu Sugama
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Masakane Yamashita
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takayuki Takahashi
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
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Pagé V, Chen JJ, Durand-Dubief M, Grabowski D, Oya E, Sansô M, Martin RD, Hébert TE, Fisher RP, Ekwall K, Tanny JC. Histone H2B Ubiquitylation Regulates Histone Gene Expression by Suppressing Antisense Transcription in Fission Yeast. Genetics 2019; 213:161-172. [PMID: 31345994 PMCID: PMC6727805 DOI: 10.1534/genetics.119.302499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/23/2019] [Indexed: 02/08/2023] Open
Abstract
Histone H2B monoubiquitylation (H2Bub1) is tightly linked to RNA polymerase II transcription elongation, and is also directly implicated in DNA replication and repair. Loss of H2Bub1 is associated with defects in cell cycle progression, but how these are related to its various functions, and the underlying mechanisms involved, is not understood. Here we describe a role for H2Bub1 in the regulation of replication-dependent histone genes in the fission yeast Schizosaccharomyces pombe H2Bub1 activates histone genes indirectly by suppressing antisense transcription of ams2+ -a gene encoding a GATA-type transcription factor that activates histone genes and is required for assembly of centromeric chromatin. Mutants lacking the ubiquitylation site in H2B or the H2B-specific E3 ubiquitin ligase Brl2 had elevated levels of ams2+ antisense transcripts and reduced Ams2 protein levels. These defects were reversed upon inhibition of Cdk9-an ortholog of the kinase component of positive transcription elongation factor b (P-TEFb)-indicating that they likely resulted from aberrant transcription elongation. Reduced Cdk9 activity also partially rescued chromosome segregation phenotypes of H2Bub1 mutants. In a genome-wide analysis, loss of H2Bub1 led to increased antisense transcripts at over 500 protein-coding genes in H2Bub1 mutants; for a subset of these, including several genes involved in chromosome segregation and chromatin assembly, antisense derepression was Cdk9-dependent. Our results highlight antisense suppression as a key feature of cell cycle-dependent gene regulation by H2Bub1, and suggest that aberrant transcription elongation may underlie the effects of H2Bub1 loss on cell cycle progression.
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Affiliation(s)
- Viviane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Jennifer J Chen
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Mickael Durand-Dubief
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm 17177, Sweden
| | - David Grabowski
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Eriko Oya
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm 17177, Sweden
| | - Miriam Sansô
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, Mount Sinai School of Medicine, New York, New York 10029
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, Mount Sinai School of Medicine, New York, New York 10029
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm 17177, Sweden
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
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10
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Chen EW, Tay NQ, Brzostek J, Gascoigne NRJ, Rybakin V. A Dual Inhibitor of Cdc7/ Cdk9 Potently Suppresses T Cell Activation. Front Immunol 2019; 10:1718. [PMID: 31402912 PMCID: PMC6670834 DOI: 10.3389/fimmu.2019.01718] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 07/09/2019] [Indexed: 01/05/2023] Open
Abstract
T cell activation is mediated by signaling pathways originating from the T cell receptor (TCR). Propagation of signals downstream of the TCR involves a cascade of numerous kinases, some of which have yet to be identified. Through a screening strategy that we have previously introduced, PHA-767491, an inhibitor of the kinases Cdc7 and Cdk9, was identified to impede TCR signaling. PHA-767491 suppressed several T cell activation phenomena, including the expression of activation markers, proliferation, and effector functions. We also observed a defect in TCR signaling pathways upon PHA-767491 treatment. Inhibition of Cdc7/Cdk9 impairs T cell responses, which could potentially be detrimental for the immune response to tumors, and also compromises the ability to resist infections. The Cdc7/Cdk9 inhibitor is a strong candidate as a cancer therapeutic, but its effect on the immune system poses a problem for clinical applications.
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Affiliation(s)
- Elijah W Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Neil Q Tay
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Immunology Programme, Centre for Life Sciences, Life Sciences Institute, National University of Singapore, Singapore, Singapore.,Centre for Life Sciences (CeLS), NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore, Singapore
| | - Joanna Brzostek
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Nicholas R J Gascoigne
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Immunology Programme, Centre for Life Sciences, Life Sciences Institute, National University of Singapore, Singapore, Singapore.,Centre for Life Sciences (CeLS), NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore, Singapore
| | - Vasily Rybakin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
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11
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Chun Y, Joo YJ, Suh H, Batot G, Hill CP, Formosa T, Buratowski S. Selective Kinase Inhibition Shows That Bur1 ( Cdk9) Phosphorylates the Rpb1 Linker In Vivo. Mol Cell Biol 2019; 39:e00602-18. [PMID: 31085683 DOI: 10.1128/MCB.00602-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/03/2019] [Indexed: 12/14/2022] Open
Abstract
Cyclin-dependent kinases play multiple roles in RNA polymerase II transcription. Cdk7/Kin28, Cdk9/Bur1, and Cdk12/Ctk1 phosphorylate the polymerase and other factors to drive the dynamic exchange of initiation and elongation complex components over the transcription cycle. We engineered strains of the yeast Saccharomyces cerevisiae for rapid, specific inactivation of individual kinases by addition of a covalent inhibitor. While effective, the sensitized kinases can display some idiosyncrasies, and inhibition can be surprisingly transient. As expected, inhibition of Cdk7/Kin28 blocked phosphorylation of the Rpb1 C-terminal domain heptad repeats at serines 5 and 7, the known target sites. However, serine 2 phosphorylation was also abrogated, supporting an obligatory sequential phosphorylation mechanism. Consistent with our previous results using gene deletions, Cdk12/Ctk1 is the predominant kinase responsible for serine 2 phosphorylation. Phosphorylation of the Rpb1 linker enhances binding of the Spt6 tandem SH2 domain, and here we show that Bur1/Cdk9 is the kinase responsible for these modifications in vivo.
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12
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Tarhriz V, Eyvazi S, Musavi M, Abasi M, Sharifi K, Ghanbarian H, Hejazi MS. Transient induction of Cdk9 in the early stage of differentiation is critical for myogenesis. J Cell Biochem 2019; 120:18854-18861. [PMID: 31257635 DOI: 10.1002/jcb.29204] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 05/24/2019] [Accepted: 05/29/2019] [Indexed: 12/29/2022]
Abstract
Cdk9 is a serine-threonine protein kinase that has been recognized as a regulator of cardiac differentiation. Recently, we have reported that transient induction of Cdk9 using noncoding RNA targeting Cdk9 sequences results in efficient cardiac differentiation. Concerning Cdk9 regulatory roles, here, we proposed whether constant overexpression of Cdk9 might influence the differentiation of myoblast C2C12 cells into myotubes. We overexpressed Cdk9 in mouse myoblast C2C12 cells to investigate its regulatory roles on myogenic differentiation. Upon Cdk9 overexpression, the expression level of myogenic regulatory factors was determined. Moreover, the expression profile of three important myomiRs consist of miR 1, 133 and 206 was examined during the differentiation process. Although Cdk9 expression is necessary for inducing differentiation in the early stage of myogenesis, continuous Cdk9 expression inhibits differentiation by modulating myomiRs and myogenic gene expression. Our results indicate that the transient induction of Cdk9 in the early stage of differentiation is critical for myogenesis.
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Affiliation(s)
- Vahideh Tarhriz
- Molecular Medicine Research Center, Biomedicine institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Shirin Eyvazi
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Musavi
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mozhgan Abasi
- Immunogenetics Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.,Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Kazem Sharifi
- Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Ghanbarian
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Saeid Hejazi
- Molecular Medicine Research Center, Biomedicine institute, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutical biotechnology, Tabriz University of Medical Sciences, Tabriz, Iran
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13
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Haudenschild DR, Carlson AK, Zignego DL, Yik JHN, Hilmer JK, June RK. Inhibition of early response genes prevents changes in global joint metabolomic profiles in mouse post-traumatic osteoarthritis. Osteoarthritis Cartilage 2019; 27:504-12. [PMID: 30572121 DOI: 10.1016/j.joca.2018.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/09/2018] [Accepted: 11/21/2018] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Although joint injury itself damages joint tissues, a substantial amount of secondary damage is mediated by the cellular responses to the injury. Cellular responses include the production and activation of proteases (MMPs, ADAMTSs, Cathepsins), and the production of inflammatory cytokines. The trajectory of cellular responses is driven by the transcriptional activation of early response genes, which requires Cdk9-dependent RNA Polymerase II phosphorylation. Our objective was to determine whether inhibition of cdk9-dependent early response gene activation affects changes in the joint metabolome. DESIGN To model post-traumatic osteoarthritis, we subjected mice to non-invasive Anterior Cruciate Ligament (ACL)-rupture joint injury. Following injury, mice were treated with flavopiridol - a potent and selective inhibitor of Cdk9 kinase activity - to inhibit Cdk9-dependent transcriptional activation, or vehicle control. Global joint metabolomics were analyzed 1 h after injury. RESULTS We found that injury induced metabolomic changes, including increases in Vitamin D3 metabolism, anandamide, and others. Inhibition of primary response gene activation immediately after injury largely prevented the global changes in the metabolomics profiles. Cluster analysis of joint metabolomes identified groups of injury-induced and drug-responsive metabolites. CONCLUSIONS Metabolomic profiling provides an instantaneous snapshot of biochemical activity representing cellular responses. We identified two sets of metabolites that change acutely after joint injury: those that require transcription of primary response genes, and those that do not. These data demonstrate the potential for inhibition of early response genes to alter the trajectory of cell-mediated degenerative changes following joint injury, which may offer novel targets for cell-mediated secondary joint damage.
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14
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Yang H, Basquin D, Pauli D, Oliver B. Drosophila melanogaster positive transcriptional elongation factors regulate metabolic and sex-biased expression in adults. BMC Genomics 2017; 18:384. [PMID: 28521739 PMCID: PMC5436443 DOI: 10.1186/s12864-017-3755-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/03/2017] [Indexed: 11/22/2022] Open
Abstract
Background Transcriptional elongation is a generic function, but is also regulated to allow rapid transcription responses. Following relatively long initiation and promoter clearance, RNA polymerase II can pause and then rapidly elongate following recruitment of positive elongation factors. Multiple elongation complexes exist, but the role of specific components in adult Drosophila is underexplored. Results We conducted RNA-seq experiments to analyze the effect of RNAi knockdown of Suppressor of Triplolethal and lilliputian. We similarly analyzed the effect of expressing a dominant negative Cyclin-dependent kinase 9 allele. We observed that almost half of the genes expressed in adults showed reduced expression, supporting a broad role for the three tested genes in steady-state transcript abundance. Expression profiles following lilliputian and Suppressor of Triplolethal RNAi were nearly identical raising the possibility that they are obligatory co-factors. Genes showing reduced expression due to these RNAi treatments were short and enriched for genes encoding metabolic or enzymatic functions. The dominant-negative Cyclin-dependent kinase 9 profiles showed both overlapping and specific differential expression, suggesting involvement in multiple complexes. We also observed hundreds of genes with sex-biased differential expression following treatment. Conclusion Transcriptional profiles suggest that Lilliputian and Suppressor of Triplolethal are obligatory cofactors in the adult and that they can also function with Cyclin-dependent kinase 9 at a subset of loci. Our results suggest that transcriptional elongation control is especially important for rapidly expressed genes to support digestion and metabolism, many of which have sex-biased function. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3755-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Haiwang Yang
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 50 South Drive, Bethesda, MD, 20892, USA.
| | - Denis Basquin
- Department of Genetics & Evolution, Sciences III, University of Geneva, Boulevard d'Yvoy 4, CH 1205, Geneva, Switzerland
| | - Daniel Pauli
- Department of Genetics & Evolution, Sciences III, University of Geneva, Boulevard d'Yvoy 4, CH 1205, Geneva, Switzerland
| | - Brian Oliver
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 50 South Drive, Bethesda, MD, 20892, USA
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15
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Hatch VL, Marin-Barba M, Moxon S, Ford CT, Ward NJ, Tomlinson ML, Desanlis I, Hendry AE, Hontelez S, van Kruijsbergen I, Veenstra GJC, Münsterberg AE, Wheeler GN. The positive transcriptional elongation factor (P-TEFb) is required for neural crest specification. Dev Biol 2016; 416:361-72. [PMID: 27343897 DOI: 10.1016/j.ydbio.2016.06.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 05/06/2016] [Accepted: 06/08/2016] [Indexed: 12/31/2022]
Abstract
Regulation of gene expression at the level of transcriptional elongation has been shown to be important in stem cells and tumour cells, but its role in the whole animal is only now being fully explored. Neural crest cells (NCCs) are a multipotent population of cells that migrate during early development from the dorsal neural tube throughout the embryo where they differentiate into a variety of cell types including pigment cells, cranio-facial skeleton and sensory neurons. Specification of NCCs is both spatially and temporally regulated during embryonic development. Here we show that components of the transcriptional elongation regulatory machinery, CDK9 and CYCLINT1 of the P-TEFb complex, are required to regulate neural crest specification. In particular, we show that expression of the proto-oncogene c-Myc and c-Myc responsive genes are affected. Our data suggest that P-TEFb is crucial to drive expression of c-Myc, which acts as a 'gate-keeper' for the correct temporal and spatial development of the neural crest.
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Affiliation(s)
- Victoria L Hatch
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Marta Marin-Barba
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Simon Moxon
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Christopher T Ford
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Nicole J Ward
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Matthew L Tomlinson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Ines Desanlis
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Adam E Hendry
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Saartje Hontelez
- Radboud University, Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Ila van Kruijsbergen
- Radboud University, Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Gert Jan C Veenstra
- Radboud University, Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Andrea E Münsterberg
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Grant N Wheeler
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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16
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Kumar V, Guru SK, Jain SK, Joshi P, Gandhi SG, Bharate SB, Bhushan S, Bharate SS, Vishwakarma RA. A chromatography-free isolation of rohitukine from leaves of Dysoxylum binectariferum: Evaluation for in vitro cytotoxicity, Cdk inhibition and physicochemical properties. Bioorg Med Chem Lett 2016; 26:3457-63. [PMID: 27363938 DOI: 10.1016/j.bmcl.2016.06.046] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/28/2016] [Accepted: 06/16/2016] [Indexed: 12/13/2022]
Abstract
Rohitukine is a chromone alkaloid isolated from an Indian medicinal plant Dysoxylum binectariferum. This natural product has led to the discovery of two clinical candidates (flavopiridol and P276-00) for the treatment of cancer. Herein, for the first time we report an efficient protocol for isolation and purification of this precious natural product in a bulk-quantity from leaves (a renewable source) of D. binectariferum (>98% purity) without use of chromatography or any acid-base treatment. Despite of the fact that this scaffold has reached up to clinical stage, particularly for leukemia; however the antileukemic activity of a parent natural product has never been investigated. Furthermore, rohitukine has never been studied for cyclin-dependent kinase (Cdk) inhibition, kinase profiling and for its experimental physicochemical properties. Thus, herein, we report in vitro cytotoxicity of rohitukine in a panel of 20 cancer cell lines (including leukemia, pancreatic, prostate, breast and CNS) and 2 normal cell lines; kinase profiling, Cdk2/9 inhibition, and physicochemical properties (solubility and stability in biological medias, pKa, LogP, LogD). In cytotoxicity screening, rohitukine displayed promising activity in HL-60 and Molt-4 (leukemia) cell lines with GI50 of 10 and 12μM, respectively. It showed inhibition of Cdk2/A and Cdk9/T1 with IC50 values of 7.3 and 0.3μM, respectively. The key interactions of rohitukine with Cdk9 was also studied by molecular modeling. Rohitukine was found to be highly water soluble (Swater=10.3mg/mL) and its LogP value was -0.55. The ionization constant of rohitukine was found to be 5.83. Rohitukine was stable in various biological media's including rat plasma. The data presented herein will help in designing better anticancer agents in future.
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Affiliation(s)
- Vikas Kumar
- Preformulation Laboratory, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Santosh K Guru
- Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Shreyans K Jain
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Natural Products Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Prashant Joshi
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Sumit G Gandhi
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Sandip B Bharate
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Shashi Bhushan
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Sonali S Bharate
- Preformulation Laboratory, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
| | - Ram A Vishwakarma
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
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17
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Abstract
Transcription elongation by RNA polymerase II (RNAP II) involves the coordinated action of numerous regulatory factors. Among these are chromatin-modifying enzymes, which generate a stereotypic and conserved pattern of histone modifications along transcribed genes. This pattern implies a precise coordination between regulators of histone modification and the RNAP II elongation complex. Here I review the pathways and molecular events that regulate co-transcriptional histone modifications. Insight into these events will illuminate the assembly of functional RNAP II elongation complexes and how the chromatin landscape influences their composition and function.
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Affiliation(s)
- Jason C Tanny
- a Department of Pharmacology and Therapeutics ; McGill University ; Montreal , Canada
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18
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Abstract
The transition between initiation and productive elongation during RNA Polymerase II (Pol II) transcription is a well-appreciated point of regulation across many eukaryotes. Elongating Pol II is modified by phosphorylation of serine 2 (Ser2) on its carboxy terminal domain (CTD) by two kinases, Bur1/Ctk1 in yeast and Cdk9/Cdk12 in metazoans. Here, we discuss the roles and regulation of these kinases and their relationship to Pol II elongation control, and focus on recent data from work in C. elegans that point out gaps in our current understand of transcription elongation.
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Affiliation(s)
- Elizabeth A Bowman
- National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
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19
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Wier AD, Mayekar MK, Héroux A, Arndt KM, VanDemark AP. Structural basis for Spt5-mediated recruitment of the Paf1 complex to chromatin. Proc Natl Acad Sci U S A 2013; 110:17290-5. [PMID: 24101474 DOI: 10.1073/pnas.1314754110] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polymerase associated factor 1 complex (Paf1C) broadly influences gene expression by regulating chromatin structure and the recruitment of RNA-processing factors during transcription elongation. The Plus3 domain of the Rtf1 subunit mediates Paf1C recruitment to genes by binding a repeating domain within the elongation factor Spt5 (suppressor of Ty). Here we provide a molecular description of this interaction by reporting the structure of human Rtf1 Plus3 in complex with a phosphorylated Spt5 repeat. We find that Spt5 binding is mediated by an extended surface containing phosphothreonine recognition and hydrophobic interfaces that interact with residues outside the Spt5 motif. Changes within these interfaces diminish binding of Spt5 in vitro and chromatin localization of Rtf1 in vivo. The structure reveals the basis for recognition of the repeat motif of Spt5, a key player in the recruitment of gene regulatory factors to RNA polymerase II.
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20
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Bagashev A, Fan S, Mukerjee R, Claudio PP, Chabrashvili T, Leng RP, Benchimol S, Sawaya BE. Cdk9 phosphorylates Pirh2 protein and prevents degradation of p53 protein. Cell Cycle 2013; 12:1569-77. [PMID: 23603988 DOI: 10.4161/cc.24733] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Several reports have pointed to the negative involvement of p53 in transcriptional regulation of the human immunodeficiency virus type 1 long-terminal repeat (HIV-1 LTR). We recently demonstrated that through their physical interaction, cdk9 phosphorylates p53 on Ser-392, leading to p53 stability and accumulation. As a result, p53 stalled transcriptional elongation of the HIV-1 LTR and significantly reduced HIV-1 replication in primary microglia and astrocytes. Therefore, we sought to identify the mechanisms used by cdk9 to allow this p53 function. Using western blot analysis, we found that cdk9 promotes inhibition and phosphorylation of Mdm2 on Ser-395, thus preventing degradation of p53, a protein that is directly involved in promoting p53 ubiquitination. On the other hand, we showed that cdk9 phosphorylates Pirh2 on Ser-211 and Thr-217 residues through their physical interaction. Phosphorylation of Pirh2 renders it inactive and may contribute to p53-inhibition of transcriptional elongation of the HIV-1 LTR. Hence, we suggest that phosphorylation of Pirh2 may be a novel target for the inhibition of HIV-1 gene expression.
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Affiliation(s)
- Asen Bagashev
- Molecular Studies of Neurodegenerative Diseases Lab, The Fels Institute for Cancer Research & Molecular Biology, Temple University School of Medicine, Philadelphia, PA, USA
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21
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Ghanbarian H, Grandjean V, Cuzin F, Rassoulzadegan M. A Network of Regulations by Small Non-Coding RNAs: The P-TEFb Kinase in Development and Pathology. Front Genet 2011; 2:95. [PMID: 22303389 PMCID: PMC3268644 DOI: 10.3389/fgene.2011.00095] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 12/07/2011] [Indexed: 11/13/2022] Open
Abstract
Part of the heterodimeric P-TEF-b element of the Pol II transcription machinery, the cyclin-dependent kinase 9 plays a critical role in gene expression. Phosphorylation of several residues in the polymerase is required for elongation of transcript. It determines the rates of transcription and thus, plays a critical role in several differentiation pathways, best documented in heart development. The synthesis and activity of the protein are tightly regulated in a coordinated manner by at least three non-coding RNAs. First, its kinase activity is reversibly inhibited by formation of a complex with the 334 nt 7SK RNA, from which it is released under conditions of stress. Then, heart development requires a maximal rate of synthesis during cardiomyocyte differentiation, followed by a decrease in the differentiated state. The latter is insured by microRNA-mediated translational inhibition. In a third mode of RNA control, increased levels of transcription are induced by small non-coding RNA molecules with sequences homologous to the transcript. Designated paramutation, this epigenetic variation, stable during development, and hereditarily transmitted in a non-Mendelian manner over several generations, is thought to be a response to the inactivation of one of the two alleles by an abnormal recombination event such as insertion of a transposon.
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