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Mikula M, Skrzypczak M, Goryca K, Paczkowska K, Ledwon JK, Statkiewicz M, Kulecka M, Grzelak M, Dabrowska M, Kuklinska U, Karczmarski J, Rumienczyk I, Jastrzebski K, Miaczynska M, Ginalski K, Bomsztyk K, Ostrowski J. Genome-wide co-localization of active EGFR and downstream ERK pathway kinases mirrors mitogen-inducible RNA polymerase 2 genomic occupancy. Nucleic Acids Res 2016; 44:10150-10164. [PMID: 27587583 PMCID: PMC5137434 DOI: 10.1093/nar/gkw763] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 08/17/2016] [Accepted: 08/23/2016] [Indexed: 01/20/2023] Open
Abstract
Genome-wide mechanisms that coordinate expression of subsets of functionally related genes are largely unknown. Recent studies show that receptor tyrosine kinases and components of signal transduction cascades including the extracellular signal-regulated protein kinase (ERK), once thought to act predominantly in the vicinity of plasma membrane and in the cytoplasm, can be recruited to chromatin encompassing transcribed genes. Genome-wide distribution of these transducers and their relationship to transcribing RNA polymerase II (Pol2) could provide new insights about co-regulation of functionally related gene subsets. Chromatin immunoprecipitations (ChIP) followed by deep sequencing, ChIP-Seq, revealed that genome-wide binding of epidermal growth factor receptor, EGFR and ERK pathway components at EGF-responsive genes was highly correlated with characteristic mitogen-induced Pol2-profile. Endosomes play a role in intracellular trafficking of proteins including their nuclear import. Immunofluorescence revealed that EGF-activated EGFR, MEK1/2 and ERK1/2 co-localize on endosomes. Perturbation of endosome internalization process, through the depletion of AP2M1 protein, resulted in decreased number of the EGFR containing endosomes and inhibition of Pol2, EGFR/ERK recruitment to EGR1 gene. Thus, mitogen-induced co-recruitment of EGFR/ERK components to subsets of genes, a kinase module possibly pre-assembled on endosome to synchronize their nuclear import, could coordinate genome-wide transcriptional events to ensure effective cell proliferation.
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Affiliation(s)
- M Mikula
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - M Skrzypczak
- University of Warsaw, CeNT, Laboratory of Bioinformatics and Systems Biology, Zwirki i Wigury 93, 02-089, Poland
| | - K Goryca
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - K Paczkowska
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - J K Ledwon
- Medical Center for Postgraduate Education, Department of Gastroenterology, Hepatology and Clinical Oncology, Roentgena 5, 02-781 Warsaw, Poland
| | - M Statkiewicz
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - M Kulecka
- Medical Center for Postgraduate Education, Department of Gastroenterology, Hepatology and Clinical Oncology, Roentgena 5, 02-781 Warsaw, Poland
| | - M Grzelak
- University of Warsaw, CeNT, Laboratory of Bioinformatics and Systems Biology, Zwirki i Wigury 93, 02-089, Poland
| | - M Dabrowska
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - U Kuklinska
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - J Karczmarski
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - I Rumienczyk
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland
| | - K Jastrzebski
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland
| | - M Miaczynska
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109, Warsaw, Poland
| | - K Ginalski
- University of Warsaw, CeNT, Laboratory of Bioinformatics and Systems Biology, Zwirki i Wigury 93, 02-089, Poland
| | - K Bomsztyk
- University of Washington, Department of Medicine, 850 Republican Street, Seattle, WA, USA
| | - J Ostrowski
- Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Genetics, Roentgena 5, 02-781 Warsaw, Poland.,Medical Center for Postgraduate Education, Department of Gastroenterology, Hepatology and Clinical Oncology, Roentgena 5, 02-781 Warsaw, Poland
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Srivastava R, Ahn SH. Modifications of RNA polymerase II CTD: Connections to the histone code and cellular function. Biotechnol Adv 2015; 33:856-72. [PMID: 26241863 DOI: 10.1016/j.biotechadv.2015.07.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/08/2015] [Accepted: 07/28/2015] [Indexed: 12/24/2022]
Abstract
At the onset of transcription, many protein machineries interpret the cellular signals that regulate gene expression. These complex signals are mostly transmitted to the indispensable primary proteins involved in transcription, RNA polymerase II (RNAPII) and histones. RNAPII and histones are so well coordinated in this cellular function that each cellular signal is precisely allocated to specific machinery depending on the stage of transcription. The carboxy-terminal domain (CTD) of RNAPII in eukaryotes undergoes extensive posttranslational modification, called the 'CTD code', that is indispensable for coupling transcription with many cellular processes, including mRNA processing. The posttranslational modification of histones, known as the 'histone code', is also critical for gene transcription through the reversible and dynamic remodeling of chromatin structure. Notably, the histone code is closely linked with the CTD code, and their combinatorial effects enable the delicate regulation of gene transcription. This review elucidates recent findings regarding the CTD modifications of RNAPII and their coordination with the histone code, providing integrative pathways for the fine-tuned regulation of gene expression and cellular function.
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Affiliation(s)
- Rakesh Srivastava
- Division of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Republic of Korea
| | - Seong Hoon Ahn
- Division of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Republic of Korea.
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Erk1/2 activity promotes chromatin features and RNAPII phosphorylation at developmental promoters in mouse ESCs. Cell 2014; 156:678-90. [PMID: 24529373 DOI: 10.1016/j.cell.2014.01.009] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/28/2013] [Accepted: 01/02/2014] [Indexed: 01/22/2023]
Abstract
Erk1/2 activation contributes to mouse ES cell pluripotency. We found a direct role of Erk1/2 in modulating chromatin features required for regulated developmental gene expression. Erk2 binds to specific DNA sequence motifs typically accessed by Jarid2 and PRC2. Negating Erk1/2 activation leads to increased nucleosome occupancy and decreased occupancy of PRC2 and poised RNAPII at Erk2-PRC2-targeted developmental genes. Surprisingly, Erk2-PRC2-targeted genes are specifically devoid of TFIIH, known to phosphorylate RNA polymerase II (RNAPII) at serine-5, giving rise to its initiated form. Erk2 interacts with and phosphorylates RNAPII at its serine 5 residue, which is consistent with the presence of poised RNAPII as a function of Erk1/2 activation. These findings underscore a key role for Erk1/2 activation in promoting the primed status of developmental genes in mouse ES cells and suggest that the transcription complex at developmental genes is different than the complexes formed at other genes, offering alternative pathways of regulation.
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Corden JL. RNA polymerase II C-terminal domain: Tethering transcription to transcript and template. Chem Rev 2013; 113:8423-55. [PMID: 24040939 PMCID: PMC3988834 DOI: 10.1021/cr400158h] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jeffry L Corden
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore Maryland 21205, United States
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Jeronimo C, Bataille AR, Robert F. The Writers, Readers, and Functions of the RNA Polymerase II C-Terminal Domain Code. Chem Rev 2013; 113:8491-522. [DOI: 10.1021/cr4001397] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Célia Jeronimo
- Institut de recherches cliniques de Montréal, Montréal, Québec,
Canada H2W 1R7
| | - Alain R. Bataille
- Institut de recherches cliniques de Montréal, Montréal, Québec,
Canada H2W 1R7
| | - François Robert
- Institut de recherches cliniques de Montréal, Montréal, Québec,
Canada H2W 1R7
- Département
de Médecine,
Faculté de Médecine, Université de Montréal, Montréal, Québec,
Canada H3T 1J4
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Rodrigues F, Thuma L, Klämbt C. The regulation of glial-specific splicing of Neurexin IV requires HOW and Cdk12 activity. Development 2012; 139:1765-76. [PMID: 22461565 DOI: 10.1242/dev.074070] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The differentiation of the blood-brain barrier (BBB) is an essential process in the development of a complex nervous system and depends on alternative splicing. In the fly BBB, glial cells establish intensive septate junctions that require the cell-adhesion molecule Neurexin IV. Alternative splicing generates two different Neurexin IV isoforms: Neurexin IV(exon3), which is found in cells that form septate junctions, and Neurexin IV(exon4), which is found in neurons that form no septate junctions. Here, we show that the formation of the BBB depends on the RNA-binding protein HOW (Held out wings), which triggers glial specific splicing of Neurexin IV(exon3). Using a set of splice reporters, we show that one HOW-binding site is needed to include one of the two mutually exclusive exons 3 and 4, whereas binding at the three further motifs is needed to exclude exon 4. The differential splicing is controlled by nuclear access of HOW and can be induced in neurons following expression of nuclear HOW. Using a novel in vivo two-color splicing detector, we then screened for genes required for full HOW activity. This approach identified Cyclin-dependent kinase 12 (Cdk12) and the splicesosomal component Prp40 as major determinants in regulating HOW-dependent splicing of Neurexin IV. Thus, in addition to the control of nuclear localization of HOW, the phosphorylation of the C-terminal domain of the RNA polymerase II by Cdk12 provides an elegant mechanism in regulating timed splicing of newly synthesized mRNA molecules.
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Affiliation(s)
- Floriano Rodrigues
- Institut für Neurobiologie, Universität Münster, Badestrasse 9, 48149 Münster, Germany
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High-temperature induction of male sterility during barley (Hordeum vulgare L.) anther development is mediated by transcriptional inhibition. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/s00497-005-0004-2] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Albert AL, Lavoie SB, Vincent M. Multisite phosphorylation of Pin1-associated mitotic phosphoproteins revealed by monoclonal antibodies MPM-2 and CC-3. BMC Cell Biol 2004; 5:22. [PMID: 15171797 PMCID: PMC420459 DOI: 10.1186/1471-2121-5-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2003] [Accepted: 06/01/2004] [Indexed: 12/31/2022] Open
Abstract
Background The peptidyl-prolyl isomerase Pin1 recently revealed itself as a new player in the regulation of protein function by phosphorylation. Pin1 isomerizes the peptide bond of specific phosphorylated serine or threonine residues preceding proline in several proteins involved in various cellular events including mitosis, transcription, differentiation and DNA damage response. Many Pin1 substrates are antigens of the phosphodependent monoclonal antibody MPM-2, which reacts with a subset of proteins phosphorylated at the G2/M transition. Results As MPM-2 is not a general marker of mitotic phosphoproteins, and as most mitotic substrates are phosphorylated more than once, we used a different phosphodependent antibody, mAb CC-3, to identify additional mitotic phosphoproteins and eventual Pin1 substrates by combining affinity purification, MALDI-TOF mass spectrometry and immunoblotting. Most CC-3-reactive phosphoproteins appeared to be known or novel MPM-2 antigens and included the RNA-binding protein p54nrb/nmt55, the spliceosomal protein SAP155, the Ki-67 antigen, MAP-1B, DNA topoisomerases II α and β, the elongation factor hSpt5 and the largest subunit of RNA polymerase II. The CC-3 mitotic antigens were also shown to be Pin1 targets. The fine CC-3- and MPM-2-epitope mapping of the RNA polymerase II carboxy-terminal domain confirmed that the epitopes were different and could be generated in vitro by distinct kinases. Finally, the post-mitotic dephosphorylation of both CC-3 and MPM-2 antigens was prevented when cellular Pin1 activity was blocked by the selective inhibitor juglone. Conclusion These observations indicate that the mitotic phosphoproteins associated with Pin1 are phosphorylated on multiple sites, suggesting combinatorial regulation of substrate recognition and isomerization.
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Affiliation(s)
- Alexandra L Albert
- CREFSIP et Département de médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Québec, Qc, Canada, G1K 7P4
| | - Sébastien B Lavoie
- CREFSIP et Département de médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Québec, Qc, Canada, G1K 7P4
| | - Michel Vincent
- CREFSIP et Département de médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Québec, Qc, Canada, G1K 7P4
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Lin PS, Tremeau-Bravard A, Dahmus ME. The repetitive C-terminal domain of RNA polymerase II: multiple conformational states drive the transcription cycle. CHEM REC 2004; 3:235-45. [PMID: 14595832 DOI: 10.1002/tcr.10063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
RNA polymerase (RNAP) II is a complex multisubunit enzyme responsible for the synthesis of mRNA in eukaryotic cells. The largest subunit contains at its C-terminus a unique domain, designated the CTD, comprised of tandem repeats of the consensus sequence Tyr(1)Ser(2)Pro(3)Thr(4)Ser(5)Pro(6)Ser(7). This repeat occurs 52 times in mammalian RNAP II. The CTD is subject to extensive phosphorylation at specific points in the transcription cycle by distinct CTD kinases that phosphorylate certain positions within the consensus repeat. The level and pattern of phosphorylation is determined by the concerted action of CTD kinases and CTD phosphatases. The highly dynamic modification by multiple CTD kinases and phosphatases generate distinct conformations of the CTD that facilitate the recruitment of specific macromolecular assemblies to RNAP II. These CTD interacting proteins influence formation of a preinitiation complex at the promoter and couple processing of the primary transcript to the elongation complex.
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Affiliation(s)
- Patrick S Lin
- Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
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Palancade B, Bensaude O. Investigating RNA polymerase II carboxyl-terminal domain (CTD) phosphorylation. ACTA ACUST UNITED AC 2003; 270:3859-70. [PMID: 14511368 DOI: 10.1046/j.1432-1033.2003.03794.x] [Citation(s) in RCA: 195] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phosphorylation of RNA polymerase II's largest subunit C-terminal domain (CTD) is a key event during mRNA metabolism. Numerous enzymes, including cell cycle-dependent kinases and TFIIF-dependent phosphatases target the CTD. However, the repetitive nature of the CTD prevents determination of phosphorylated sites by conventional biochemistry methods. Fortunately, a panel of monoclonal antibodies is available that distinguishes between phosphorylated isoforms of RNA polymerase II's (RNAP II) largest subunit. Here, we review how successful these tools have been in monitoring RNAP II phosphorylation changes in vivo by immunofluorescence, chromatin immunoprecipitation and immunoblotting experiments. The CTD phosphorylation pattern is precisely modified as RNAP II progresses along the genes and is involved in sequential recruitment of RNA processing factors. One of the most popular anti-phosphoCTD Igs, H5, has been proposed in several studies as a landmark of RNAP II molecules engaged in transcription. Finally, we discuss how global RNAP II phosphorylation changes are affected by the physiological context such as cell stress and embryonic development.
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Affiliation(s)
- Benoît Palancade
- Génétique Moléculaire, UMR 8541 CNRS, Ecole Normale Supérieure, Paris, France
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Lin PS, Dubois MF, Dahmus ME. TFIIF-associating carboxyl-terminal domain phosphatase dephosphorylates phosphoserines 2 and 5 of RNA polymerase II. J Biol Chem 2002; 277:45949-56. [PMID: 12351650 DOI: 10.1074/jbc.m208588200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The carboxyl-terminal domain (CTD) of the largest RNA polymerase (RNAP) II subunit undergoes reversible phosphorylation throughout the transcription cycle. The unphosphorylated form of RNAP II is referred to as IIA, whereas the hyperphosphorylated form is known as IIO. Phosphorylation occurs predominantly at serine 2 and serine 5 within the CTD heptapeptide repeat and has functional implications for RNAP II with respect to initiation, elongation, and transcription-coupled RNA processing. In an effort to determine the role of the major CTD phosphatase (FCP1) in regulating events in transcription that appear to be influenced by serine 2 and serine 5 phosphorylation, the specificity of FCP1 was examined. FCP1 is capable of dephosphorylating heterogeneous RNAP IIO populations of HeLa nuclear extracts. The extent of dephosphorylation at specific positions was assessed by immunoreactivity with monoclonal antibodies specific for phosphoserine 2 or phosphoserine 5. As an alternative method to assess FCP1 specificity, RNAP IIO isozymes were prepared in vitro by the phosphorylation of purified calf thymus RNAP IIA with specific CTD kinases and used as substrates for FCP1. FCP1 dephosphorylates serine 2 and serine 5 with comparable efficiency. Accordingly, the specificity of FCP1 is sufficiently broad to dephosphorylate RNAP IIO at any point in the transcription cycle irrespective of the site of serine phosphorylation within the consensus repeat.
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Affiliation(s)
- Patrick S Lin
- Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
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Lin PS, Marshall NF, Dahmus ME. CTD phosphatase: role in RNA polymerase II cycling and the regulation of transcript elongation. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2002; 72:333-65. [PMID: 12206456 DOI: 10.1016/s0079-6603(02)72074-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The repetitive C-terminal domain (CTD) of the largest RNA polymerase II subunit plays a critical role in the regulation of gene expression. The activity of the CTD is dependent on its state of phosphorylation. A variety of CTD kinases act on RNA polymerase II at specific steps in the transcription cycle and preferentially phosphorylate distinct positions within the CTD consensus repeat. A single CTD phosphatase has been identified and characterized that in concert with CTD kinases establishes the level of CTD phosphorylation. The involvement of CTD phosphatase in controlling the progression of RNAP II around the transcription cycle, the mobilization of stored RNAP IIO, and the regulation of transcript elongation and RNA processing is discussed.
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Dirgahayu P, Fukumoto S, Miura K, Hirai K. Excretory/secretory products from plerocercoids of Spirometra erinaceieuropaei suppress the TNF-alpha gene expression by reducing phosphorylation of ERK1/2 and p38 MAPK in macrophages. Int J Parasitol 2002; 32:1155-62. [PMID: 12117498 DOI: 10.1016/s0020-7519(02)00090-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We previously reported that excretory/secretory products from plerocercoids of Spirometra erinaceieuropaei suppress gene expression and production of tumour necrosis factor-alpha in murine macrophages stimulated with lipopolysaccharide. The present study investigated the suppressive mechanisms of tumour necrosis factor-alpha mRNA by excretory/secretory products in lipopolysaccharide-stimulated murine macrophages. Electrophoretic mobility shift assay and supershift assay revealed that neither nuclear translocation of nuclear factor-kappa B nor conformation of the p50/p65 nuclear factor-kappa B subunits was affected by the treatment of excretory/secretory products in lipopolysaccharide-stimulated macrophages. Inhibition of extracellular signal-regulated protein kinase 1/2 with PD98059 or p38 mitogen-activated protein kinase with SB203580 partially reduced tumour necrosis factor-alpha mRNA expression, and a combination of the two inhibitors additionally suppressed the level of tumour necrosis factor-alpha mRNA, revealing that both pathways are crucial for full induction of the gene. Northern blot analysis showed that excretory/secretory products additionally suppressed tumour necrosis factor-alpha mRNA expression in cells treated with PD98059 or SB208530 and, in turn, we found that excretory/secretory products reduced phosphorylation of extracellular signal-regulated protein kinase 1/2 and p38 mitogen-activated protein kinase in lipopolysaccharide-stimulated macrophages by Western blot analysis. This is the first report demonstrating that excretory/secretory products from parasites suppress tumour necrosis factor-alpha mRNA expression by reducing phosphorylation of extracellular signal-regulated protein kinase 1/2 and p38 mitogen-activated protein kinase without any effect on nuclear factor-kappa B activity in macrophages stimulated with lipopolysaccharide. We hypothesise that excretory/secretory products may enable this parasite to survive within the host.
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Affiliation(s)
- Paramasari Dirgahayu
- Department of Molecular Medical Zoology, Faculty of Medicine, Tottori University, 86 Nishi-cho, 683-8503 Yonago, Japan
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Bonnet F, Vigneron M, Bensaude O, Dubois MF. Transcription-independent phosphorylation of the RNA polymerase II C-terminal domain (CTD) involves ERK kinases (MEK1/2). Nucleic Acids Res 1999; 27:4399-404. [PMID: 10536148 PMCID: PMC148722 DOI: 10.1093/nar/27.22.4399] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The largest subunit of the mammalian RNA polymerase II possesses a C-terminal domain (CTD) consisting of 52 repeats of the consensus sequence, Tyr(1)-Ser(2)-Pro(3)-Thr(4)-Ser(5)-Pro(6)-Ser(7). Phosphorylation of the CTD is known to play a key role in gene expression. We now show that treatments such as osmotic and oxidative shocks or serum stimulation generate a new type of phosphorylated subunit, the IIm form. This IIm form might be generated in vivo by ERK-type MAP kinase phosphorylation as: (i) ERK1/2 are major CTD kinases found in cell extracts; (ii) the immunoreactivity of the IIm form against a panel of monoclonal antibodies indicates that the CTD is exclusively phosphorylated on Ser-5 in the repeats, like RNA polymerase II phosphorylated in vitro by an ERK1/2; and (iii) the IIm form does not appear when ERK activation is prevented by treating cells with low concentrations of highly specific inhibitors of MEK1/2. Since the IIm subunit is not affected by inhibition of transcription and is not bound to chromatin, it does not participate in transcription.
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Affiliation(s)
- F Bonnet
- Laboratoire de Régulation de l'Expression Génétique, CNRS UMR 8541, Ecole Normale Supérieure, 46 rue d'Ulm, 75230 Paris Cedex 05, France
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Latham KE. Mechanisms and control of embryonic genome activation in mammalian embryos. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 193:71-124. [PMID: 10494621 DOI: 10.1016/s0074-7696(08)61779-9] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Activation of transcription within the embryonic genome (EGA) after fertilization is a complex process requiring a carefully coordinated series of nuclear and cytoplasmic events, which collectively ensure that the two parental genomes can be faithfully reprogrammed and restructured before transcription occurs. Available data indicate that inappropriate transcription of some genes during the period of nuclear reprogramming can have long-term detrimental effects on the embryo. Therefore, precise control over the time of EGA is essential for normal embryogenesis. In most mammals, genome activation occurs in a stepwise manner. In the mouse, for example, some transcription occurs during the second half of the one-cell stage, and then a much greater phase of genome activation occurs in two waves during the two-cell stage, with the second wave producing the largest onset of de novo gene expression. Changes in nuclear structure, chromatin structure, and cytoplasmic macromolecular content appear to regulate these periods of transcriptional activation. A model is presented in which a combination of cell cycle-dependent events and both translational and posttranslational regulatory mechanisms within the cytoplasm play key roles in mediating and regulating EGA.
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Affiliation(s)
- K E Latham
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Bensaude O, Bonnet F, Cassé C, Dubois MF, Nguyen VT, Palancade B. Regulated phosphorylation of the RNA polymerase II C-terminal domain (CTD). Biochem Cell Biol 1999. [DOI: 10.1139/o99-047] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The largest subunit of RNA polymerase II has an intriguing feature in its carboxyl-terminal domain (CTD) that consists of multiple repeats of an evolutionary conserved motif of seven amino acids. CTD phosphorylation plays a pivotal role in controlling mRNA synthesis and maturation. In exponentially growing cells, the phosphate turnover on the CTD is fast; it is blocked by common inhibitors of transcription, such as 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole and actinomycin D. Transcription-independent changes in CTD phosphorylation are observed at critical developmental stages, such as meiosis and early development.Key words: RNA polymerase II, phosphorylation, transcription inhibitors, cyclin-dependent kinases, development.
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Lavoie SB, Albert AL, Thibodeau A, Vincent M. Heat shock-induced alterations in phosphorylation of the largest subunit of RNA polymerase II as revealed by monoclonal antibodies CC-3 and MPM-2. Biochem Cell Biol 1999. [DOI: 10.1139/o99-037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The phosphorylation of the carboxy-terminal domain of the largest subunit of RNA polymerase II plays an important role in the regulation of transcriptional activity and is also implicated in pre-mRNA processing. Different stresses, such as a heat shock, induce a marked alteration in the phosphorylation of this domain. The expression of stress genes by RNA polymerase II, to the detriment of other genes, could be attributable to such modifications of the phosphorylation sites. Using two phosphodependent antibodies recognizing distinct hyperphosphorylated forms of RNA polymerase II largest subunit, we studied the phosphorylation state of the subunit in different species after heat shocks of varying intensities. One of these antibodies, CC-3, preferentially recognizes the carboxy-terminal domain of the largest subunit under normal conditions, but its reactivity is diminished during stress. In contrast, the other antibody used, MPM-2, demonstrated a strong reactivity after a heat shock in most species studied. Therefore, CC-3 and MPM-2 antibodies discriminate between phosphoisomers that may be functionally different. Our results further indicate that the pattern of phosphorylation of RNA polymerase II in most species varies in response to environmental stress.Key words: RNA polymerase II, heat shock, phosphorylation, CC-3, MPM-2.
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Albert A, Lavoie S, Vincent M. A hyperphosphorylated form of RNA polymerase II is the major interphase antigen of the phosphoprotein antibody MPM-2 and interacts with the peptidyl-prolyl isomerase Pin1. J Cell Sci 1999; 112 ( Pt 15):2493-500. [PMID: 10393805 DOI: 10.1242/jcs.112.15.2493] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The monoclonal antibody MPM-2 recognizes a subset of M phase phosphoproteins in a phosphorylation-dependent manner. It is believed that phosphorylation at MPM-2 antigenic sites could regulate mitotic events since most of the MPM-2 antigens identified to date have M phase functions. In addition, many of these proteins are substrates of the mitotic regulator Pin1, a peptidyl-prolyl isomerase which is present throughout the cell cycle and which is thought to alter its mitotic targets by changing their conformation. In interphase cells, most MPM-2 reactivity is confined to nuclear speckles. We report here that a hyperphosphorylated form of the RNA polymerase II largest subunit is the major MPM-2 interphase antigen. These findings were made possible by the availability of another monoclonal antibody, CC-3, that was previously used to identify a 255 kDa nuclear matrix protein associated with spliceosomal components as a hyperphosphorylated form of the RNA polymerase II largest subunit. MPM-2 recognizes a phosphoepitope of the large subunit that becomes hyperphosphorylated upon heat shock in contrast to the phosphoepitope defined by CC-3, whose reactivity is diminished by the heat treatment. Therefore, these two antibodies may discriminate between distinct functional forms of RNA polymerase II. We also show that RNA polymerase II large subunit interacts with Pin1 in HeLa cells. Pin1 may thus regulate transcriptional and post-transcriptional events by catalyzing phosphorylation-dependent conformational changes of the large RNA polymerase II subunit.
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Affiliation(s)
- A Albert
- Département de médecine and CREFSIP, Pavillon C.-E.-Marchand, Université Laval, Ste-Foy, Québec, Canada, G1K 7P4
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20
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Hirst M, Kobor MS, Kuriakose N, Greenblatt J, Sadowski I. GAL4 is regulated by the RNA polymerase II holoenzyme-associated cyclin-dependent protein kinase SRB10/CDK8. Mol Cell 1999; 3:673-8. [PMID: 10360183 DOI: 10.1016/s1097-2765(00)80360-3] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Phosphorylation of the yeast transcription factor GAL4 at S699 is required for efficient galactose-inducible transcription. We demonstrate that this site is a substrate for the RNA polymerase holoenzyme-associated CDK SRB10. S699 phosphorylation requires SRB10 in vivo, and this site is phosphorylated by purified SRB10/ SRB11 CDK/cyclin in vitro. RNA Pol II holoenzymes purified from WT yeast phosphorylate GAL4 at sites observed in vivo whereas holoenzymes from srb10 yeast are incapable of phosphorylating GAL4 at S699. Mutations at GAL4 S699 and srb10 are epistatic for GAL induction, demonstrating that SRB10 regulates GAL4 activity through this phosphorylation in vivo. These results demonstrate a function for the SRB10/ CDK8 holoenzyme-associated CDK that involves regulation of transactivators by phosphorylation during transcriptional activation.
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Affiliation(s)
- M Hirst
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
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21
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Rickert P, Corden JL, Lees E. Cyclin C/CDK8 and cyclin H/CDK7/p36 are biochemically distinct CTD kinases. Oncogene 1999; 18:1093-102. [PMID: 10023686 DOI: 10.1038/sj.onc.1202399] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phosphorylation of the carboxyl-terminal domain (CTD) of RNA polymerase II is important for basal transcriptional processes in vivo and for cell viability. Several kinases, including certain cyclin-dependent kinases, can phosphorylate this substrate in vitro. It has been proposed that differential CTD phosphorylation by different kinases may regulate distinct transcriptional processes. We have found that two of these kinases, cyclin C/CDK8 and cyclin H/CDK7/p36, can specifically phosphorylate distinct residues in recombinant CTD substrates. This difference in specificity may be largely due to their varying ability to phosphorylate lysine-substituted heptapeptide repeats within the CTD, since they phosphorylate the same residue in CTD consensus heptapeptide repeats. Furthermore, this substrate specificity is reflected in vivo where cyclin C/ CDK8 and cyclin H/CDK7/p36 can differentially phosphorylate an endogenous RNA polymerase II substrate. Several small-molecule kinase inhibitors have different specificities for these related kinases, indicating that these enzymes have diverse active-site conformations. These results suggest that cyclin C/CDK8 and cyclin H/CDK7/p36 are physically distinct enzymes that may have unique roles in transcriptional regulation mediated by their phosphorylation of specific sites on RNA polymerase II.
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Affiliation(s)
- P Rickert
- Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, California 94304, USA
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22
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Nagasaka Y, Nakamura K. Modulation of the heat-induced activation of mitogen-activated protein (MAP) kinase by quercetin. Biochem Pharmacol 1998; 56:1151-5. [PMID: 9802325 DOI: 10.1016/s0006-2952(98)00253-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Effects of quercetin, a bioflavonoid compound, on heat-induced activation of mitogen-activated protein (MAP) kinase in rat hepatoma (H4) cells were examined. Quercetin decreased cell viability and induced DNA fragmentation in heat-shocked H4 cells. MAP kinase in heat-shocked cells was activated and reached a peak at 1 hr after the heat shock, and then gradually decreased. Quercetin inhibited the heat-induced activation of MAP kinase observed at 1 hr after heat shock, but markedly stimulated MAP kinase activity at 4 hr after heat shock. Thus, quercetin modulated the heat-induced activation of MAP kinase in a biphasic manner. Present observations indicate that quercetin modulates protein phosphorylation, especially that controled by MAP kinase, in early events of heat shock response.
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Affiliation(s)
- Y Nagasaka
- Department of Nutrition, Yamaguchi Prefectural University, Japan.
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23
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Egyházi E, Ossoinak A, Lee JM, Greenleaf AL, Mäkelä TP, Pigon A. Heat-shock-specific phosphorylation and transcriptional activity of RNA polymerase II. Exp Cell Res 1998; 242:211-21. [PMID: 9665818 DOI: 10.1006/excr.1998.4112] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The carboxyl-terminal domain (CTD) of the largest RNA polymerase II (pol II) subunit is a target for extensive phosphorylation in vivo. Using in vitro kinase assays it was found that several different protein kinases can phosphorylate the CTD including the transcription factor IIH-associated CDK-activating CDK7 kinase (R. Roy, J. P. Adamczewski, T. Seroz, W. Vermeulen, J. P. Tassan, L. Schaeffer, E. A. Nigg, J. H. Hoeijmakers, and J. M. Egly, 1994, Cell 79, 1093-1101). Here we report the colocalization of CDK7 and the phosphorylated form of CTD (phosphoCTD) to actively transcribing genes in intact salivary gland cells of Chironomus tentans. Following a heat-shock treatment, both CDK7 and pol II staining disappear from non-heat-shock genes concomitantly with the abolishment of transcriptional activity of these genes. In contrast, the actively transcribing heat-shock genes, manifested as chromosomal puff 5C on chromosome IV (IV-5C), stain intensely for phosphoCTD, but are devoid of CDK7. Furthermore, the staining of puff IV-5C with anti-PCTD antibodies was not detectably influenced by the TFIIH kinase and transcription inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB). Following heat-shock treatment, the transcription of non-heat-shock genes was completely eliminated, while newly formed heat-shock gene transcripts emerged in a DRB-resistant manner. Thus, heat shock in these cells induces a rapid clearance of CDK7 from the non-heat-shock genes, indicating a lack of involvement of CDK7 in the induction and function of the heat-induced genes. The results taken together suggest the existence of heat-shock-specific CTD phosphorylation in living cells. This phosphorylation is resistant to DRB treatment, suggesting that not only phosphorylation but also transcription of heat-shock genes is DRB resistant and that CDK7 in heat shock cells is not associated with TFIIH.
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Affiliation(s)
- E Egyházi
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
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24
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Ratner JN, Balasubramanian B, Corden J, Warren SL, Bregman DB. Ultraviolet radiation-induced ubiquitination and proteasomal degradation of the large subunit of RNA polymerase II. Implications for transcription-coupled DNA repair. J Biol Chem 1998; 273:5184-9. [PMID: 9478972 DOI: 10.1074/jbc.273.9.5184] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have shown previously that UV radiation and other DNA-damaging agents induce the ubiquitination of a portion of the RNA polymerase II large subunit (Pol II LS). In the present study UV irradiation of repair-competent fibroblasts induced a transient reduction of the Pol II LS level; new protein synthesis restored Pol II LS to the base-line level within 16-24 h. In repair-deficient xeroderma pigmentosum cells, UV radiation-induced ubiquitination of Pol II LS was followed by a sustained reduction of Pol II LS level. In both normal and xeroderma pigmentosum cells, the ubiquitinated Pol II LS had a hyperphosphorylated COOH-terminal domain (CTD), which is characteristic of elongating Pol II. The portion of Pol II LS whose steady-state level diminished most quickly had a relatively hypophosphorylated CTD. The ubiquitinated residues did not map to the CTD. Importantly, UV-induced reduction of Pol II LS level in repair-competent or -deficient cells was inhibited by the proteasome inhibitors lactacystin or MG132. These data demonstrate that UV-induced ubiquitination of Pol II LS is followed by its degradation in the proteasome. These results suggest, contrary to a current model of transcription-coupled DNA repair, that elongating Pol II complexes which arrest at intragenic DNA lesions may be aborted rather than resuming elongation after repair takes place.
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Affiliation(s)
- J N Ratner
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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25
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Patturajan M, Schulte RJ, Sefton BM, Berezney R, Vincent M, Bensaude O, Warren SL, Corden JL. Growth-related changes in phosphorylation of yeast RNA polymerase II. J Biol Chem 1998; 273:4689-94. [PMID: 9468530 DOI: 10.1074/jbc.273.8.4689] [Citation(s) in RCA: 202] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The largest subunit of RNA polymerase II contains a unique C-terminal domain (CTD) consisting of tandem repeats of the consensus heptapeptide sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7. Two forms of the largest subunit can be separated by SDS-polyacrylamide gel electrophoresis. The faster migrating form termed IIA contains little or no phosphate on the CTD, whereas the slower migrating II0 form is multiply phosphorylated. CTD kinases with different phosphoryl acceptor specificities are able to convert IIA to II0 in vitro, and different phosphoisomers have been identified in vivo. In this paper we report the binding specificities of a set of monoclonal antibodies that recognize different phosphoepitopes on the CTD. Monoclonal antibodies like H5 recognize phosphoserine in position 2, whereas monoclonal antibodies like H14 recognize phosphoserine in position 5. The relative abundance of these phosphoepitopes changes when growing yeast enter stationary phase or are heat-shocked. These results indicate that phosphorylation of different CTD phosphoacceptor sites are independently regulated in response to environmental signals.
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Affiliation(s)
- M Patturajan
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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26
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Vanden Berghe W, Plaisance S, Boone E, De Bosscher K, Schmitz ML, Fiers W, Haegeman G. p38 and extracellular signal-regulated kinase mitogen-activated protein kinase pathways are required for nuclear factor-kappaB p65 transactivation mediated by tumor necrosis factor. J Biol Chem 1998; 273:3285-90. [PMID: 9452444 DOI: 10.1074/jbc.273.6.3285] [Citation(s) in RCA: 584] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Interleukin-6 (IL-6) is a pleiotropic cytokine, which is involved in inflammatory and immune responses, acute phase reactions, and hematopoiesis. In the mouse fibrosarcoma cell line L929, the nuclear factor (NF)-kappaB plays a crucial role in IL-6 gene expression mediated by tumor necrosis factor (TNF). The levels of the activated factor do not, however, correlate with the variations of IL-6 gene transcription; therefore, other factors and/or regulatory mechanisms presumably modulate the levels of IL-6 mRNA production. Upon analysis of various deletion and point-mutated variants of the human IL-6 gene promoter coupled to a reporter gene, we screened for possible cooperating transcription factors. Even the smallest deletion variant, containing almost exclusively a NF-kappaB-responsive sequence preceding the IL-6 minimal promoter, as well as a recombinant construction containing multiple kappaB-motifs, could still be stimulated with TNF. We observed that the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 was able to repress TNF-stimulated expression of the IL-6 gene, as well as of a kappaB-dependent reporter gene construct, without affecting the levels of NF-kappaB binding to DNA. Furthermore, we clearly show that, using a nuclear Gal4 "one-hybrid" system, the MAPK inhibitors SB203580 and PD0980589 have a direct repressive effect on the transactivation potential of the p65 kappaB subunit. Therefore, we conclude that, in addition to cytoplasmic activation and DNA binding of NF-kappaB, the p38 and extracellular signal-regulated kinase MAPK pathways act as necessary cooperative mechanisms to regulate TNF-induced IL-6 gene expression by modulating the transactivation machinery.
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Affiliation(s)
- W Vanden Berghe
- Laboratory of Molecular Biology, Flanders Interuniversity Institute for Biotechnology and University of Gent, B-9000 Gent, Belgium
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27
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Yamakawa A, Kameoka Y, Hashimoto K, Yoshitake Y, Nishikawa K, Tanihara K, Date T. cDNA cloning and chromosomal mapping of genes encoding novel protein kinases termed PKU-alpha and PKU-beta, which have nuclear localization signal. Gene X 1997; 202:193-201. [PMID: 9427565 DOI: 10.1016/s0378-1119(97)00495-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have cloned cDNAs for novel serine/threonine protein kinases (PK), termed PKU-alpha and PKU-beta, by screening a bacteriophage expression library for kinase activity. Sequence analysis of PKU-alpha and PKU-beta genes revealed that their open reading frames (ORF) were 2151 and 2361 nucleotides (nt) encoding polypeptides of 717 and 787 amino acid (aa) residues, respectively. The deduced aa sequences of PKU-alpha and PKU-beta contained typical serine/threonine PK domains at the C-terminal region and were 86% identical to each other, indicating that they belong to the same PK family. Northern analysis reveals that they are expressed in nearly all human tissues and in cultured cells. The genes for PKU-alpha and PKU-beta were mapped to chromosome 17q23 and 8p12-p22, respectively, by fluorescence in situ hybridization. The proteins encoded by both cDNAs contain a putative nuclear localization signal (NLS) in their N-terminal region. These signals are likely to function in nuclear localization. Glutathione S-transferase (GST)-fusions to regions of PKU-alpha and beta containing the NLS were efficiently localized to the nucleus. In addition, PKU-beta transiently expressed in COS-1 cells was predominantly nuclear. PKU-alpha and PKU-beta differ: a consensus sequence for a nt binding motif is present near the NLS of PKU-beta. These results suggest that PKU-alpha and beta may phosphorylate serine and/or threonine residues on similar proteins, but their activities are regulated through distinct interactions with a nuclear component.
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Affiliation(s)
- A Yamakawa
- Department of Biochemistry, Kanazawa Medical University, Uchinada, Ishikawa, Japan
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28
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Bellier S, Chastant S, Adenot P, Vincent M, Renard JP, Bensaude O. Nuclear translocation and carboxyl-terminal domain phosphorylation of RNA polymerase II delineate the two phases of zygotic gene activation in mammalian embryos. EMBO J 1997; 16:6250-62. [PMID: 9321404 PMCID: PMC1326309 DOI: 10.1093/emboj/16.20.6250] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In mammalian embryos, zygotic gene transcription initiates after a limited number of cell divisions through a two-step process termed the zygotic gene activation (ZGA). Here we report that RNA polymerase II undergoes major changes in mouse and rabbit preimplantation embryos during the ZGA. In transcriptionally inactive unfertilized oocytes, the RNA polymerase II largest subunit is predominantly hyperphosphorylated on its carboxy-terminal domain (CTD). The CTD is markedly dephosphorylated several hours after fertilization, before the onset of a period characterized by a weak transcriptional activity. The largest subunit of RNA polymerase II then lacks immunological and drug-sensitivity characteristics related to its phosphorylation by the TFIIH-associated kinase and gradually translocates into the nuclei independently of DNA replication and mitosis. A phosphorylation pattern of the largest subunit, close to that observed in somatic cells, is established in both mouse and rabbit embryos at the stage when transcription becomes a requirement for further development (respectively at the 2- and 8/16-cell stage). As these events occurred in the presence of actinomycin D, the nuclear translocation of RNA polymerase II and the phosphorylation of the CTD might be major determinants of ZGA.
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Affiliation(s)
- S Bellier
- Génétique Moléculaire, URA 1302 CNRS, Ecole Normale Supérieure, 46 rue d'Ulm, 75230 Cedex 05, France
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29
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Lee JM, Greenleaf AL. Modulation of RNA polymerase II elongation efficiency by C-terminal heptapeptide repeat domain kinase I. J Biol Chem 1997; 272:10990-3. [PMID: 9110987 DOI: 10.1074/jbc.272.17.10990] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Hyperphosphorylation of the C-terminal heptapeptide repeat domain (CTD) of the RNA polymerase II largest subunit has been suggested to play a key role in regulating transcription initiation and elongation. To facilitate investigating functional consequences of CTD phosphorylation we developed new templates, the double G-less cassettes, which make it possible to assay simultaneously the level of initiation and the efficiency of elongation. Using these templates, we examined the effects of yeast CTD kinase I or CTD kinase inhibitors on transcription and CTD phosphorylation in HeLa nuclear extracts. Our results showed that polymerase II elongation efficiency and CTD phosphorylation are greatly reduced by CTD kinase inhibitors, whereas both are greatly increased by CTD kinase I; in contrast, transcription initiation is much less affected. These results demonstrate that CTD kinase I modulates the elongation efficiency of RNA polymerase II and are consistent with the idea that one function of CTD phosphorylation is to promote effective production of long transcripts by stimulating the elongation efficiency of RNA polymerase II.
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Affiliation(s)
- J M Lee
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA
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30
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Bellier S, Dubois MF, Nishida E, Almouzni G, Bensaude O. Phosphorylation of the RNA polymerase II largest subunit during Xenopus laevis oocyte maturation. Mol Cell Biol 1997; 17:1434-40. [PMID: 9032270 PMCID: PMC231868 DOI: 10.1128/mcb.17.3.1434] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Xenopus laevis oogenesis is characterized by an active transcription which ceases abruptly upon maturation. To survey changes in the characteristics of the transcriptional machinery which might contribute to this transcriptional arrest, the phosphorylation status of the RNA polymerase II largest subunit (RPB1 subunit) was analyzed during oocyte maturation. We found that the RPB1 subunit accumulates in large quantities from previtellogenic early diplotene oocytes up to fully grown oocytes. The C-terminal domain (CTD) of the RPB1 subunit was essentially hypophosphorylated in growing oocytes from Dumont stage IV to stage VI. Upon maturation, the proportion of hyperphosphorylated RPB1 subunits increased dramatically and abruptly. The hyperphosphorylated RPB1 subunits were dephosphorylated within 1 h after fertilization or heat shock of the matured oocytes. Extracts from metaphase II-arrested oocytes showed a much stronger CTD kinase activity than extracts from prophase stage VI oocytes. Most of this kinase activity was attributed to the activated Xp42 mitogen-activated protein (MAP) kinase, a MAP kinase of the ERK type. Making use of artificial maturation of the stage VI oocyte through microinjection of a recombinant stable cyclin B1, we observed a parallel activation of Xp42 MAP kinase and phosphorylation of RPB1. Both events required protein synthesis, which demonstrated that activation of p34(cdc2)off kinase was insufficient to phosphorylate RPB1 ex vivo and was consistent with a contribution of the Xp42 MAP kinase to RPB1 subunit phosphorylation. These results further support the possibility that the largest RNA polymerase II subunit is a substrate of the ERK-type MAP kinases during oocyte maturation, as previously proposed during stress or growth factor stimulation of mammalian cells.
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Affiliation(s)
- S Bellier
- Génétique Moléculaire, URA 1302 CNRS, Ecole Normale Supérieure, Paris, France
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31
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Dubois MF, Vincent M, Vigneron M, Adamczewski J, Egly JM, Bensaude O. Heat-shock inactivation of the TFIIH-associated kinase and change in the phosphorylation sites on the C-terminal domain of RNA polymerase II. Nucleic Acids Res 1997; 25:694-700. [PMID: 9016617 PMCID: PMC146510 DOI: 10.1093/nar/25.4.694] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The C-terminal domain (CTD) of the RNA polymerase II largest subunit (RPB1) plays a central role in transcription. The CTD is unphosphorylated when the polymerase assembles into a preinitiation complex of transcription and becomes heavily phosphorylated during promoter clearance and entry into elongation of transcription. A kinase associated to the general transcription factor TFIIH, in the preinitiation complex, phosphorylates the CTD. The TFIIH-associated CTD kinase activity was found to decrease in extracts from heat-shocked HeLa cells compared to unstressed cells. This loss of activity correlated with a decreased solubility of the TFIIH factor. The TFIIH-kinase impairment during heat-shock was accompanied by the disappearance of a particular phosphoepitope (CC-3) on the RPB1 subunit. The CC-3 epitope was localized on the C-terminal end of the CTD and generated in vitro when the RPB1 subunit was phosphorylated by the TFIIH-associated kinase but not by another CTD kinase such as MAP kinase. In apparent discrepancy, the overall RPB1 subunit phosphorylation increased during heat-shock. The decreased activity in vivo of the TFIIH kinase might be compensated by a stress-activated CTD kinase such as MAP kinase. These results also suggest that heat-shock gene transcription may have a weak requirement for TFIIH kinase activity.
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Affiliation(s)
- M F Dubois
- Laboratoire de Génétique Moléculaire, URA CNRS 1302, Ecole Normale Supérieure, Paris, France
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32
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Chu B, Soncin F, Price BD, Stevenson MA, Calderwood SK. Sequential phosphorylation by mitogen-activated protein kinase and glycogen synthase kinase 3 represses transcriptional activation by heat shock factor-1. J Biol Chem 1996; 271:30847-57. [PMID: 8940068 DOI: 10.1074/jbc.271.48.30847] [Citation(s) in RCA: 305] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Mammalian heat shock genes are regulated at the transcriptional level by heat shock factor-1 (HSF-1), a sequence-specific transcription factor. We have examined the role of serine phosphorylation of HSF-1 in the regulation of heat shock gene transcription. Our experiments show that mitogen-activated protein kinases (MAPKs) of the ERK-1 family phosphorylate HSF-1 on serine residues and repress the transcriptional activation of the heat shock protein 70B (HSP70B) promoter by HSF-1 in vivo. These effects of MAPK are transmitted through a specific serine residue (Ser-303) located in a proline-rich sequence within the transcriptional regulatory domain of human HSF-1. However, despite the importance of Ser-303 in transmitting the signal from the MAPK cascade to HSP70 transcription, there was no evidence that Ser-303 could be phosphorylated by MAPK in vitro, although an adjacent residue (Ser-307) was avidly phosphorylated by MAPK. Further studies revealed that Ser-303 is phosphorylated by glycogen synthase kinase 3 (GSK3) through a mechanism dependent on primary phosphorylation of Ser-307 by MAPK. Secondary phosphorylation of Ser-303 by GSK3 may thus repress the activity of HSF-1, and its requirement for priming by MAPK phosphorylation of Ser-307 provides a potential link between the MAPK cascade and HSF-1. Our experiments thus indicate that MAPK is a potent inhibitor of HSF-1 function and may be involved in repressing the heat shock response during normal growth and development and deactivating the heat shock response during recovery from stress.
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Affiliation(s)
- B Chu
- Dana Farber Cancer Institute and Joint Center for Radiation Therapy, Harvard Medical School, Boston, Massachusetts 02115, USA.
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33
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Marshall NF, Peng J, Xie Z, Price DH. Control of RNA polymerase II elongation potential by a novel carboxyl-terminal domain kinase. J Biol Chem 1996; 271:27176-83. [PMID: 8900211 DOI: 10.1074/jbc.271.43.27176] [Citation(s) in RCA: 506] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The entry of RNA polymerase II into a productive mode of elongation is controlled, in part, by the postinitiation activity of positive transcription elongation factor b (P-TEFb) (Marshall, N. F., and Price, D. H. (1995) J. Biol. Chem. 270, 12335-12338). We report here that removal of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II abolishes productive elongation. Correspondingly, we found that P-TEFb can phosphorylate the CTD of pure RNA polymerase II. Furthermore, P-TEFb can phosphorylate the CTD of RNA polymerase II when the polymerase is in an early elongation complex. Both the function and kinase activity of P-TEFb are blocked by the drugs 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) and H-8. P-TEFb is distinct from transcription factor IIH (TFIIH) because the two factors have no subunits in common, P-TEFb is more sensitive to DRB than is TFIIH, and most importantly, TFIIH cannot substitute functionally for P-TEFb. We propose that phosphorylation of the CTD by P-TEFb controls the transition from abortive into productive elongation mode.
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Affiliation(s)
- N F Marshall
- Department of Biochemistry, University of Iowa, Iowa City, Iowa 52242, USA
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34
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Nguyen VT, Giannoni F, Dubois MF, Seo SJ, Vigneron M, Kédinger C, Bensaude O. In vivo degradation of RNA polymerase II largest subunit triggered by alpha-amanitin. Nucleic Acids Res 1996; 24:2924-9. [PMID: 8760875 PMCID: PMC146057 DOI: 10.1093/nar/24.15.2924] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Alpha-Amanitin is a well-known specific inhibitor of RNA polymerase II (RNAPII) in vitro and in vivo. It is a cyclic octapeptide which binds with high affinity to the largest subunit of RNAPII, RPB1. We have found that in murine fibroblasts exposure to alpha-amanitin triggered degradation of the RPB1 subunit, while other RNAPII subunits, RPB5 and RPB8, remained almost unaffected. Transcriptional inhibition in alpha-amanitin-treated cells was slow and closely followed the disappearance of RPB1. The degradation rate of RPB1 was alpha-amanitin dose dependent and was not a consequence of transcriptional arrest. Alpha-Amanitin-promoted degradation of RPB1 was prevented in cells exposed to actinomycin D, another transcriptional inhibitor. Epitope-tagged recombinant human RPB1 subunits were expressed in mouse fibroblasts. In cells exposed to alpha-amanitin the wild-type recombinant subunit was degraded like the endogenous protein, but a mutated alpha-amanitin-resistant subunit remained unaffected. Hence, alpha-amanitin did not activate a proteolytic system, but instead its binding to mRPB1 likely represented a signal for degradation. Thus, in contrast to other inhibitors, such as actinomycin D or 5,6-dichloro-1-beta-D-ribofuranosyl-benzimidazole, which reversibly act on transcription, inhibition by alpha-amanitin cannot be but an irreversible process because of the destruction of RNAPII.
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Affiliation(s)
- V T Nguyen
- Laboratoire de Génétique Moléculaire, Ecole Normale Superieure, Paris
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Bensaude O, Bellier S, Dubois MF, Giannoni F, Nguyen VT. Heat-shock induced protein modifications and modulation of enzyme activities. EXS 1996; 77:199-219. [PMID: 8856976 DOI: 10.1007/978-3-0348-9088-5_13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Upon heat stress, the cell physiology is profoundly altered. The extent of the alterations depends on the severity of the stress and may lead to cell death. The heat shock response is an array of metabolic changes characterized by the impairment of major cellular functions and by an adaptative reprogramming of the cell metabolism. The enhanced synthesis of the HSPs is a spectacular manifestation of this reprogramming. Numerous post translational modifications of proteins occur in response to heat stress and can be related to altered cellular functions. Some proteins are heat-denatured and temporarily inactivated. Heat-denaturation is reversible, chaperones may contribute to the repair. The extent of heat-denaturation depends on the cell metabolism: (a) it is attenuated in thermotolerant cells or in cells overexpressing the appropriate chaperones (b) it is enhanced in energy-deprived cells. Covalent modifications may also rapidly alter protein function. Changes in protein glycosylation, methylation, acetylation, farnesylation, ubiquitination have been found to occur during stress. But protein phosphorylation is the most studied modification. Several protein kinase cascades are activated, among which the various mitogen activated protein kinase (MAP kinase) cascades which are also triggered by a wide range of stimuli. As a possible consequence, stress modifies the phosphorylation status and the activity of components from the transcriptional and translational apparatuses. The same kinases also target key enzymes of the cellular metabolism. Protein denaturation results in constitutive hsp titration, this titration is a signal to trigger the heat-shock gene transcription and to activate some of the protein kinase cascades.
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Affiliation(s)
- O Bensaude
- Génétique Moléculaire, Ecole Normale Supérieure, Paris, France
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