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Li Z, Miller MW, Luo J. Effects of prenatal exposure to ethanol on the cyclin-dependent kinase system in the developing rat cerebellum. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2002; 139:237-45. [PMID: 12480138 DOI: 10.1016/s0165-3806(02)00573-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Prenatal exposure to ethanol inhibits neurogenesis in the developing cerebellum. Cyclin-dependent kinases (CDKs) are a family of protein kinases that play multiple roles in the regulation of cell proliferation, differentiation and survival. The activity of CDKs is positively regulated by CDK activators, cyclins, and negatively regulated by CDK inhibitors (CDKIs). We hypothesize that impaired cerebellar development induced by gestational ethanol exposure is mediated by disruption of the CDK system. Pregnant rats were fed ad libitum with an ethanol-containing liquid diet (Et) or pair-fed an isocaloric control diet (Ct). Cerebella were collected from pups (postnatal day (P) 0 through P21) and examined for CDK, cyclin, or CDKI expression using a quantitative immunoblotting procedure. In Ct-treated rats, the expression of CDK2 and its activator, cyclin A, paralleled the pattern of granule cell proliferation. Prenatal ethanol exposure produced a significant down-regulation of CDK2/cyclin A expression. Although the amounts of CDK4/CDK6 and their activator, cyclin D2, did not oscillate during postnatal development, their expression in Et-treated pups was significantly (P<0.05) higher than in controls. The expression of a CDK inhibitor, p27(Kip), was inversely correlated to proliferation of cerebellar granule progenitors. Prenatal ethanol exposure caused the down-regulation of p27(Kip) between P0 and P21. Thus, prenatal exposure to ethanol disturbed the expression of cell cycle machineries in the postnatal cerebellum. This may account for the teratogenic effects of ethanol on the developing cerebellum.
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Affiliation(s)
- Zheng Li
- Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Robert C. Byrd Health Science Center, P.O. Box 9177, Morgantown, WV 26506, USA
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Hiroi N, Ito T, Yamamoto H, Ochiya T, Jinno S, Okayama H. Mammalian Rcd1 is a novel transcriptional cofactor that mediates retinoic acid-induced cell differentiation. EMBO J 2002; 21:5235-44. [PMID: 12356739 PMCID: PMC129043 DOI: 10.1093/emboj/cdf521] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Rcd1, initially identified as a factor essential for the commitment to nitrogen starvation-invoked differentiation in fission yeast, is one of the most conserved proteins found across eukaryotes, and its mammalian homolog is expressed in a variety of differentiating tissues. Here we show that mammalian Rcd1 is a novel transcriptional cofactor and is critically involved in the commitment step in the retinoic acid-induced differentiation of F9 mouse teratocarcinoma cells, at least in part, via forming complexes with retinoic acid receptor and activation transcription factor-2 (ATF-2). In addition, antisense oligonucleotide treatment of embryonic mouse lung explants suggests that Rcd1 also plays a role in retinoic acid-controlled lung development.
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Affiliation(s)
| | - Takaaki Ito
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033,
Department of Pathology, Yokohama City University, School of Medicine, Kanazawa-ku, Yokohama 236-0004 and Section for Studies on Metastasis, National Cancer Center Institute, Chuo-ku, Tokyo 104-0045, Japan Corresponding author e-mail: o
| | - Hanako Yamamoto
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033,
Department of Pathology, Yokohama City University, School of Medicine, Kanazawa-ku, Yokohama 236-0004 and Section for Studies on Metastasis, National Cancer Center Institute, Chuo-ku, Tokyo 104-0045, Japan Corresponding author e-mail: o
| | - Takahiro Ochiya
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033,
Department of Pathology, Yokohama City University, School of Medicine, Kanazawa-ku, Yokohama 236-0004 and Section for Studies on Metastasis, National Cancer Center Institute, Chuo-ku, Tokyo 104-0045, Japan Corresponding author e-mail: o
| | | | - Hiroto Okayama
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033,
Department of Pathology, Yokohama City University, School of Medicine, Kanazawa-ku, Yokohama 236-0004 and Section for Studies on Metastasis, National Cancer Center Institute, Chuo-ku, Tokyo 104-0045, Japan Corresponding author e-mail: o
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56
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Ouwens D, de Ruiter ND, van der Zon GC, Carter AP, Schouten J, van der Burgt C, Kooistra K, Bos JL, Maassen J, van Dam H. Growth factors can activate ATF2 via a two-step mechanism: phosphorylation of Thr71 through the Ras-MEK-ERK pathway and of Thr69 through RalGDS-Src-p38. EMBO J 2002; 21:3782-93. [PMID: 12110590 PMCID: PMC126107 DOI: 10.1093/emboj/cdf361] [Citation(s) in RCA: 179] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Transcription factor ATF2 regulates gene expression in response to environmental changes. Upon exposure to cellular stresses, the mitogen-activated proteinkinase (MAPK) cascades including SAPK/JNK and p38 can enhance ATF2's transactivating function through phosphorylation of Thr69 and Thr71. How ever, the mechanism of ATF2 activation by growth factors that are poor activators of JNK and p38 is still elusive. Here, we show that in fibroblasts, insulin, epidermal growth factor (EGF) and serum activate ATF2 via a so far unknown two-step mechanism involving two distinct Ras effector pathways: the Raf-MEK-ERK pathway induces phosphorylation of ATF2 Thr71, whereas subsequent ATF2 Thr69 phosphorylation requires the Ral-RalGDS-Src-p38 pathway. Cooperation between ERK and p38 was found to be essential for ATF2 activation by these mitogens; the activity of p38 and JNK/SAPK in growth factor-stimulated fibroblasts is insufficient to phosphorylate ATF2 Thr71 or Thr69 + 71 significantly by themselves, while ERK cannot dual phosphorylate ATF2 Thr69 + 71 efficiently. These results reveal a so far unknown mechanism by which distinct MAPK pathways and Ras effector pathways cooperate to activate a transcription factor.
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Affiliation(s)
- D.Margriet Ouwens
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Nancy D. de Ruiter
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Gerard C.M. van der Zon
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Andrew P. Carter
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Jan Schouten
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Corina van der Burgt
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Klaas Kooistra
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Johannes L. Bos
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - J.Antonie Maassen
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
| | - Hans van Dam
- Department of Molecular Cell Biology, Section of Signal Transduction and Centre for Biomedical Genetics, Section Gene Regulation, Leiden University Medical Centre, Wassenaarseweg 72, 2333 AL Leiden and Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK Present address: Leadd BV, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands Corresponding author e-mail:
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57
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Amorino GP, Hamilton VM, Valerie K, Dent P, Lammering G, Schmidt-Ullrich RK. Epidermal growth factor receptor dependence of radiation-induced transcription factor activation in human breast carcinoma cells. Mol Biol Cell 2002; 13:2233-44. [PMID: 12134064 PMCID: PMC117308 DOI: 10.1091/mbc.01-12-0572] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Ionizing radiation (1-5 Gy) activates the epidermal growth factor receptor (EGFR), a major effector of the p42/44 mitogen-activated protein kinase (MAPK) pathway. MAPK and its downstream effector, p90 ribosomal S6 kinase (p90RSK), phosphorylate transcription factors involved in cell proliferation. To establish the role of the EGFR/MAPK pathway in radiation-induced transcription factor activation, MDA-MB-231 human breast carcinoma cells were examined using specific inhibitors of signaling pathways. Gel-shift analysis revealed three different profile groups: 1) transcription factors that responded to both radiation (2 Gy) and epidermal growth factor (EGF) (CREB, Egr, Ets, and Stat3); 2) factors that responded to radiation, but not EGF (C/EBP and Stat1); and 3) those that did not respond significantly to either radiation or EGF (AP-1 and Myc). Within groups 1 and 2, a two- to fivefold maximum stimulation of binding activity was observed at 30-60 min after irradiation. Interestingly, only transcription factors that responded to EGF had radiation responses significantly inhibited by the EGFR tyrosine kinase inhibitor, AG1478; these responses were also abrogated by farnesyltransferase inhibitor (FTI) or PD98059, inhibitors of Ras and MEK1/2, respectively. Moreover, radiation-induced increases in CREB and p90RSK phosphorylation and activation of Stat3 and Egr-1 reporter constructs by radiation were all abolished by AG1478. These data demonstrate a distinct radiation response profile at the transcriptional level that is dependent on enhanced EGFR/Ras/MAPK signaling.
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Affiliation(s)
- George P Amorino
- Department of Radiation Oncology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA
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60
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Tarn C, Lee S, Hu Y, Ashendel C, Andrisani OM. Hepatitis B virus X protein differentially activates RAS-RAF-MAPK and JNK pathways in X-transforming versus non-transforming AML12 hepatocytes. J Biol Chem 2001; 276:34671-80. [PMID: 11461911 DOI: 10.1074/jbc.m104105200] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The hepatitis B virus (HBV) X protein (pX) is implicated in hepatocarcinogenesis of chronic HBV patients by an unknown mechanism. Activities of pX likely relevant to hepatocyte transformation include activation of the mitogenic RAS-RAF-MAPK and JNK pathways. To assess the importance of mitogenic pathway activation by pX in transformation, we employed a cellular model system composed of two tetracycline-regulated, pX-expressing cell lines, constructed in AML12-immortalized hepatocytes. This system includes the differentiated 3pX-1 and the de-differentiated 4pX-1 hepatocytes. Our studies have demonstrated that conditional pX expression transforms only 3pX-1 cells. Here, comparative in vitro kinase assays and various in vivo analyses demonstrate that pX affects an inverse activation of RAS-RAF-MAPK and JNK pathways in 3pX-1 versus 4pX-1 cells. Sustained pX-dependent RAS-RAF-MAPK pathway activation is observed in pX-transforming 3pX-1 cells, whereas sustained pX-dependent JNK pathway activation is observed in pX non-transforming 4pX-1 cells. This differential, pX-dependent mitogenic pathway activation affects differential activation of cAMP-response element-binding protein and c-Jun and determines the proliferative response of 3pX-1 and 4pX-1 cells. Furthermore, tetracycline-regulated, pX-NLS-expressing cell lines demonstrate that expression of the nuclear pX-NLS variant minimally activates the RAS-RAF-MAPK pathway and results in markedly reduced transformation. These results link sustained, pX-mediated activation of RAS-RAF-MAPK pathway to hepatocyte transformation.
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Affiliation(s)
- C Tarn
- Department of Basic Medical Sciences and Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, USA
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