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Wang F, Liang L, Ling S, Yu Y, Chen T, Xu F, Gong Z, Han L. Clinical characteristics and genotype analysis of five infants with cblX type of methylmalonic acidemia. Zhejiang Da Xue Xue Bao Yi Xue Ban 2022; 51:298-305. [PMID: 36207831 PMCID: PMC9511482 DOI: 10.3724/zdxbyxb-2022-0194] [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: 04/20/2022] [Accepted: 05/30/2022] [Indexed: 06/16/2023]
Abstract
OBJECTIVE To investigate the clinical and genetic characteristics of infants with cobalamin (cbl) X type of methylmalonic acidemia (MMA). METHODS The clinical data of 5 infants with cblX type of MMA diagnosed in Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine and Shanghai Children's Hospital from the year 2016 to 2020 were collected. The levels of blood acylcarnitines were detected by tandem mass spectrometry, the levels of urinary organic acids were detected by gas-chromatography mass spectrometry, the pathogenic genes were detected by whole exon gene sequencing, and the effect of new pathogenic mutations on three-dimensional protein structure was predicted by bioinformatics analysis. RESULTS Five infants with cblX type were diagnosed, including 4 males and 1 female, and the onset age was 0-6 months. The main clinical manifestations of 4 males were intractable epilepsy, mental and motor retardation, metabolic abnormalities presented mild increase of blood homocysteine level. Among them, 3 cases were accompanied by slight increase of urinary methylmalonic acid, and 1 case was accompanied by increase of blood propionylcarnitine (C3) and C3/acetylcarnitine (C2). Gene detection found that 2 cases carried a same hemizygous mutation c.344C>T (p.A115V) of HCFC1 gene, which was the most reported mutation, and the other 2 cases carried novel pathogenic mutations, c.92G>A (p.R31Q) and c.166G>C (p.V56L). These 3 gene mutations located in the Kelch domain of HCFC1 protein. One female infant carried a benign mutation of c.3731G>T (p.R1244L). Her clinical symptoms were mild, and only the urinary methylmalonic acid was slightly increased. CONCLUSIONS The clinical manifestations of children with cblX type of MMA are intractable epilepsy, mental and motor retardation, and other serious neurological symptoms. Their metabolic abnormalities present the increase of blood homocysteine with methylmalonic acid (urinary methylmalonic acid or/and blood C3, C3/C2). The clinical and biochemical phenotypes are separated, so the diagnosis should be in combination with the results of gene testing.
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Affiliation(s)
- Fei Wang
- 1. Department of Endocrinology, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200062, China
| | - Lili Liang
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
| | - Shiying Ling
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
| | - Yue Yu
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
| | - Ting Chen
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
| | - Feng Xu
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
| | - Zhuwen Gong
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
| | - Lianshu Han
- 2. Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai 200092, China
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Shima H, Ando R, Tamahara T, Igarashi K. [Extensive analysis of protein phosphorylation: An example of transcription factor Bach2]. Seikagaku 2016; 88:31-35. [PMID: 27025005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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3
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Shojaee S, Caeser R, Buchner M, Park E, Swaminathan S, Hurtz C, Geng H, Chan LN, Klemm L, Hofmann WK, Qiu YH, Zhang N, Coombes KR, Paietta E, Molkentin J, Koeffler HP, Willman CL, Hunger SP, Melnick A, Kornblau SM, Müschen M. Erk Negative Feedback Control Enables Pre-B Cell Transformation and Represents a Therapeutic Target in Acute Lymphoblastic Leukemia. Cancer Cell 2015; 28:114-28. [PMID: 26073130 PMCID: PMC4565502 DOI: 10.1016/j.ccell.2015.05.008] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 02/05/2015] [Accepted: 05/12/2015] [Indexed: 11/20/2022]
Abstract
Studying mechanisms of malignant transformation of human pre-B cells, we found that acute activation of oncogenes induced immediate cell death in the vast majority of cells. Few surviving pre-B cell clones had acquired permissiveness to oncogenic signaling by strong activation of negative feedback regulation of Erk signaling. Studying negative feedback regulation of Erk in genetic experiments at three different levels, we found that Spry2, Dusp6, and Etv5 were essential for oncogenic transformation in mouse models for pre-B acute lymphoblastic leukemia (ALL). Interestingly, a small molecule inhibitor of DUSP6 selectively induced cell death in patient-derived pre-B ALL cells and overcame conventional mechanisms of drug-resistance.
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Affiliation(s)
- Seyedmehdi Shojaee
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Rebecca Caeser
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA; Department of Haematology, University of Cambridge, Cambridge CB2 0AH, UK
| | - Maike Buchner
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Eugene Park
- Department of Haematology, University of Cambridge, Cambridge CB2 0AH, UK
| | - Srividya Swaminathan
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Christian Hurtz
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Huimin Geng
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Lai N Chan
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Lars Klemm
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Wolf-Karsten Hofmann
- III. Medizinische Klinik, Medizinische Fakultät Mannheim, Universität Heidelberg, Heidelberg 68167, Germany
| | - Yi Hua Qiu
- Department of Leukemia, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Nianxiang Zhang
- Department of Bioinformatics and Computational Biology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Kevin R Coombes
- Department of Bioinformatics and Computational Biology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Jeffery Molkentin
- Howard Hughes Medical Institute and Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, OH 45247, USA
| | - H Phillip Koeffler
- Division of Hematology and Oncology, Cedars Sinai Medical Center, Los Angeles, CA 90095, USA; Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Cheryl L Willman
- Department of Pathology, University of New Mexico Cancer Center, Albuquerque, NM 87102, USA
| | - Stephen P Hunger
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ari Melnick
- Departments of Medicine and Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Steven M Kornblau
- Department of Leukemia, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Markus Müschen
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA.
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Juang BT, Izeta A, O'Hare P, Luisi BF. Purification and characterization of the Caenorhabditis elegans HCF protein and domains of human HCF. Biochemistry 2005; 44:10396-405. [PMID: 16042417 DOI: 10.1021/bi050357l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human cellular factor (HCF) is a multidomain protein that is implicated in processes of cell cycle progression, and it is recruited into a multicomponent assembly that triggers the expression of the herpes simplex virus genome. The amino-terminal domain of HCF has been proposed to form a "kelch" type beta-propeller fold, and the carboxy-terminal domain contains a repeat of a fibronectin-like motif. We describe the expression, purification, and characterization of the domains from the human HCF and of the full-length HCF from Caenorhabditis elegans. The purified recombinant C. elegans HCF can substitute for the human HCF in efficiently forming a multiprotein complex on a herpes simplex virus promoter element. As noted in earlier studies, a segment of human HCF encompassing the human kelch domain forms a stable complex on a viral promoter element. The purified fibronectin domain can also be recruited into this complex, but not into the stable complex formed with the minimal kelch domain. These results suggest that the fibronectin domain can interact with HCF in the transcriptional activating complex and that the association requires a region outside the putative beta-propeller.
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Affiliation(s)
- Bi-Tzen Juang
- Department of Biochemistry, University of Cambridge, UK
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Deléhouzée S, Yoshikawa T, Sawa C, Sawada JI, Ito T, Omori M, Wada T, Yamaguchi Y, Kabe Y, Handa H. GABP, HCF-1 and YY1 are involved in Rb gene expression during myogenesis. Genes Cells 2005; 10:717-31. [PMID: 15966902 DOI: 10.1111/j.1365-2443.2005.00873.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Muscle cell differentiation, or myogenesis, is a well-characterized process and involves the expression of specific sets of genes in an orderly manner. A prerequisite for myogenesis is the exit from the cell cycle, which is associated with the up-regulation of the tumor suppressor Rb. In this study, we set to investigate the regulatory mechanism of the Rb promoter that allows adequate up-regulation in differentiating myoblasts. We report that Rb expression is regulated by the transcription factors GABP, HCF-1 and YY1. Before induction of differentiation, Rb is expressed at a low level and GABP and YY1 are both present on the promoter. YY1, which exerts an inhibitory effect on Rb expression, is removed from the promoter as cells advance through myogenesis and translocates from the nucleus to the cytoplasm. On the other hand, upon induction of differentiation, the GABP cofactor HCF-1 is recruited to and coactivates the promoter with GABP. RNAi-mediated knock-down of HCF-1 results in inhibition of Rb up-regulation as well as myotube formation. These results indicate that the Rb promoter is subject to regulation by positive and negative factors and that this intricate activation mechanism is critical to allow the accurate Rb gene up-regulation observed during myogenesis.
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Affiliation(s)
- Sophie Deléhouzée
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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Julien E, Herr W. A switch in mitotic histone H4 lysine 20 methylation status is linked to M phase defects upon loss of HCF-1. Mol Cell 2005; 14:713-25. [PMID: 15200950 DOI: 10.1016/j.molcel.2004.06.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Revised: 04/23/2004] [Accepted: 04/27/2004] [Indexed: 11/24/2022]
Abstract
The abundant chromatin-associated human factor HCF-1 is a heterodimeric complex of HCF-1N and HCF-1C subunits that are essential for two stages of the cell cycle. The HCF-1N subunit promotes G1 phase progression, whereas the HCF-1C subunit ensures proper cytokinesis at completion of M phase. How the HCF-1C subunit functions is unknown. Here, we show that HCF-1C subunit depletion causes extensive mitotic defects, including a switch from monomethyl to dimethyl lysine 20 of histone H4 (H4-K20) and defective chromosome alignment and segregation. Consistent with these activities, the HCF-1C subunit can associate with chromatin independently of the HCF-1N subunit and regulates the expression of the H4-K20 methyltransferase PR-Set7. Indeed, upregulation of PR-Set7 expression upon loss of HCF-1 leads to improper mitotic H4-K20 methylation and cytokinesis defects. These results establish the HCF-1C subunit as an important M phase regulator and suggest that H4-K20 methylation status contributes to chromosome behavior during mitosis and proper cytokinesis.
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Affiliation(s)
- Eric Julien
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
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Narayanan A, Nogueira ML, Ruyechan WT, Kristie TM. Combinatorial transcription of herpes simplex virus and varicella zoster virus immediate early genes is strictly determined by the cellular coactivator HCF-1. J Biol Chem 2004; 280:1369-75. [PMID: 15522876 DOI: 10.1074/jbc.m410178200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mammalian transcriptional coactivator host cell factor-1 (HCF-1) functions in concert with Oct-1 and VP16 to assemble the herpes simplex virus (HSV) immediate early (IE) transcription enhancer core complexes that mediate the high level transcription of these genes upon infection. Although this transcriptional model has been well characterized in vitro, the requirements and significance of the components have not been addressed. Oct-1 was previously determined to be critical but not essential for HSV IE gene expression. In contrast, RNA interference-mediated depletion of HCF-1 resulted in abrogation of HSV IE gene expression. The HSV IE gene enhancer domain is a model of combinatorial transcription and consists of the core enhancer and multiple binding sites for factors such as Sp1 and GA-binding protein. It was striking that HCF-1 was strictly required for VP16-mediated transcriptional induction via the core enhancer as well as for basal level transcription mediated by GA-binding protein and Sp1. HCF-1 was also found to be essential for the induction of varicella zoster virus IE gene expression by ORF10, the VZV ortholog of the HSV IE transactivator VP16, and the autostimulatory IE62 protein. The critical dependence upon HCF-1 demonstrates that this cellular component is a key factor for control of HSV and VZV IE gene expression by functioning as the common element for distinct factors cooperating at the IE gene enhancers. The requirements for this protein supports the model whereby the regulated transport of HCF-1 from the cytoplasm to the nucleus in sensory neurons may control IE gene expression and reactivation of these viruses from the latent state.
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Affiliation(s)
- Aarthi Narayanan
- Laboratory of Viral Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892, USA
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Myslinski E, Krol A, Carbon P. Characterization of snRNA and snRNA-type genes in the pufferfish Fugu rubripes. Gene 2004; 330:149-58. [PMID: 15087134 DOI: 10.1016/j.gene.2004.01.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2003] [Revised: 12/22/2003] [Accepted: 01/26/2004] [Indexed: 11/19/2022]
Abstract
Vertebrate snRNA and snRNA-type genes occur in independent transcription units with external promoters. The transcription level from the basal promoter is enhanced by the distal sequence element DSE. This element contains almost invariably two activator submotifs, the Staf binding site and the octamer motif, recruiting the Staf and Oct-1 transcriptional activators. In the present work, database search identified 35 snRNA and snRNA-type genes in the genome sequence of the pufferfish Fugu rubripes. Sequence comparisons of promoter elements, determination of template activities by microinjection into Xenopus oocytes and DNA binding assays of the transcriptional activators led to the surprising finding that only two Fugu genes conform to the general scheme with the expected two submotifs in the DSE. Distinctively, all the other DSEs harbor a unique Staf binding site. Also striking was the observation that the tRNA(Sec), and the snRNA genes that are tandemly repeated, are transcribed from promoter-less DSEs. Evolutionary implications of these results are discussed.
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Affiliation(s)
- Evelyne Myslinski
- UPR 9002 du CNRS, Structure des Macromolécules Biologiques et Mécanismes de Reconnaissance, Institut de Biologie Moléculaire et Cellulaire 15, rue René Descartes, 67084 Strasbourg Cedex, France
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Yokoyama A, Wang Z, Wysocka J, Sanyal M, Aufiero DJ, Kitabayashi I, Herr W, Cleary ML. Leukemia proto-oncoprotein MLL forms a SET1-like histone methyltransferase complex with menin to regulate Hox gene expression. Mol Cell Biol 2004; 24:5639-49. [PMID: 15199122 PMCID: PMC480881 DOI: 10.1128/mcb.24.13.5639-5649.2004] [Citation(s) in RCA: 514] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
MLL (for mixed-lineage leukemia) is a proto-oncogene that is mutated in a variety of human leukemias. Its product, a homolog of Drosophila melanogaster trithorax, displays intrinsic histone methyltransferase activity and functions genetically to maintain embryonic Hox gene expression. Here we report the biochemical purification of MLL and demonstrate that it associates with a cohort of proteins shared with the yeast and human SET1 histone methyltransferase complexes, including a homolog of Ash2, another Trx-G group protein. Two other members of the novel MLL complex identified here are host cell factor 1 (HCF-1), a transcriptional coregulator, and the related HCF-2, both of which specifically interact with a conserved binding motif in the MLL(N) (p300) subunit of MLL and provide a potential mechanism for regulating its antagonistic transcriptional properties. Menin, a product of the MEN1 tumor suppressor gene, is also a component of the 1-MDa MLL complex. Abrogation of menin expression phenocopies loss of MLL and reveals a critical role for menin in the maintenance of Hox gene expression. Oncogenic mutant forms of MLL retain an ability to interact with menin but not other identified complex components. These studies link the menin tumor suppressor protein with the MLL histone methyltransferase machinery, with implications for Hox gene expression in development and leukemia pathogenesis.
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Affiliation(s)
- Akihiko Yokoyama
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
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Abstract
The mammalian transcriptional coactivator HCF-1 is a critical component of the multiprotein herpes simplex virus immediate early gene enhancer core complex. The protein has also been implicated in basic cellular processes such as cell-cycle progression, transcriptional coactivation, and mRNA processing. Functions have been attributed to HCF-1 primarily from analyses of protein-protein interactions and from the cell-cycle-arrested phenotype of an HCF-1 temperature-sensitive mutant. However, neither the mechanisms involved nor specific cellular transcriptional targets have been identified. As the protein is essential for cell viability and proliferation, a genetic system was developed to specifically sequester the nuclear factor in the cell cytoplasm in a regulated manner. This approach exhibits no significant cell toxicity yet clearly demonstrates the requirement of available nuclear HCF-1 for herpes simplex virus immediate early gene expression during productive infection. Additionally, cellular transcriptional events were identified that contribute to understanding the functions ascribed to the protein and implicate the protein in events that impact the regulation of critical cellular processes.
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Affiliation(s)
- Bharat Khurana
- Laboratory of Viral Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Abstract
The Zinc Finger Homeodomain Enhancer-binding Protein (Zfhep) is involved in skeletal patterning, immune cell, muscle, and brain development, and is necessary for life. Zfhep contains a single central homeodomain (HD) adjacent to an isolated zinc finger, the function of which is unknown. The placement of a zinc finger so close to a homeodomain is novel in nature. The aim of this work was to characterize the Zfhep homeodomain (HD) or the zinc finger homeodomain (ZHD), with respect to DNA-binding and protein-protein interactions. Glutathione-S-transferase (GST) fusion proteins containing either just the HD or both the zinc finger and HD (ZHD) were expressed in E. coli. The GST fusion protein affinity-binding assay demonstrated that Zfhep ZHD interacts specifically with the POU domain of the Oct-1 transcription factor. The adjacent zinc finger is required since Zfhep HD alone does not interact with Oct-1 POU domain. Furthermore, ZHD does not bind to the POU homeodomain lacking the POU specific region. These results demonstrate that the Zfhep zinc finger homeodomain motif functions as a protein-binding domain in vitro, and suggests that Zfhep may modulate the activity of POU domain transcription factors. However, neither the Zfhep ZHD nor the HD bound DNA in EMSA or selected a DNA-binding site from a pool of random oligonucleotides. This is the first demonstration of a function for the HD region of Zfhep, which is the first case of a bi-partite domain requiring both a zinc finger and a HD for binding to protein.
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Affiliation(s)
- Gregory E. Smith
- Biochemistry and Molecular Biology and Center for Genetics and Molecular Medicine University of Louisville Health Sciences Center Louisville, KY 40292
| | - Douglas S. Darling
- Biochemistry and Molecular Biology and Center for Genetics and Molecular Medicine University of Louisville Health Sciences Center Louisville, KY 40292
- Periodontics, Endodontics and Dental Hygiene, and Center for Genetics and Molecular Medicine University of Louisville Health Sciences Center Louisville, KY 40292
- To whom correspondence should be addressed at University of Louisville School of Dentistry 501 South Preston St., Room 209 Louisville, KY 40292 Tel: (502) 852-5508 FAX: (502) 852-1317
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Rave-Harel N, Givens ML, Nelson SB, Duong HA, Coss D, Clark ME, Hall SB, Kamps MP, Mellon PL. TALE homeodomain proteins regulate gonadotropin-releasing hormone gene expression independently and via interactions with Oct-1. J Biol Chem 2004; 279:30287-97. [PMID: 15138251 PMCID: PMC2935805 DOI: 10.1074/jbc.m402960200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) is the central regulator of reproductive function. Expression of the GnRH gene is confined to a rare population of neurons scattered throughout the hypothalamus. Restricted expression of the rat GnRH gene is driven by a multicomponent enhancer and an evolutionarily conserved promoter. Oct-1, a ubiquitous POU homeodomain transcription factor, was identified as an essential factor regulating GnRH transcription in the GT1-7 hypothalamic neuronal cell line. In this study, we conducted a two-hybrid interaction screen in yeast using a GT1-7 cDNA library to search for specific Oct-1 cofactors. Using this approach, we isolated Pbx1b, a TALE homeodomain transcription factor that specifically associates with Oct-1. We show that heterodimers containing Pbx/Prep1 or Pbx/Meis1 TALE homeodomain proteins bind to four functional elements within the GnRH regulatory region, each in close proximity to an Oct-1-binding site. Cotransfection experiments indicate that TALE proteins are essential for GnRH promoter activity in the GT1-7 cells. Moreover, Pbx1 and Oct-1, as well as Prep1 and Oct-1, form functional complexes that enhance GnRH gene expression. Finally, Pbx1 is expressed in GnRH neurons in embryonic as well as mature mice, suggesting that the associations between TALE homeodomain proteins and Oct-1 regulate neuron-specific expression of the GnRH gene in vivo.
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Affiliation(s)
- Naama Rave-Harel
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Marjory L. Givens
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Shelley B. Nelson
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Hao A. Duong
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Djurdjica Coss
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Melody E. Clark
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Sara Barth Hall
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
| | - Mark P. Kamps
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, California 92903
| | - Pamela L. Mellon
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California 92903
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92903
- To whom correspondence should be addressed: Dept. of Reproductive Medicine, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0674; Tel.: 858-534-1312; Fax: 858-534-1438;
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Izeta A, Malcomber S, O'Rourke D, Hodgkin J, O'Hare P. A C-terminal targeting signal controls differential compartmentalisation of Caenorhabditis elegans host cell factor (HCF) to the nucleus or mitochondria. Eur J Cell Biol 2004; 82:495-504. [PMID: 14629117 DOI: 10.1078/0171-9335-00341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HCF-1 (host cell factor 1) is a human protein originally identified as a component of the VP16 transcription complex. A related protein HCF-2 is also present in humans and while at least HCF-1 appears to be required for normal cell growth there is currently little information on the precise cellular role(s) of these proteins. C. elegans contains a single HCF orthologue (CeHCF) which is very closely related to human HCF-2. To contribute to an understanding of the activities of these proteins here we analyse the subcellular localisation of the CeHCF protein in live transgenic worms and in mammalian cells. We constructed a green fluorescent protein (GFP) fusion of CeHCF and studied localisation after ectopic expression under the control of a heat shock protein promoter. The CeHCF-GFP protein accumulated in the cell nuclei at every stage of development and in a wide variety of cell types. Nuclear accumulation with nucleolar sparing was evident on the larvae and adult stages, but not earlier in development in which the protein accumulated diffusely in the nucleoplasm. Surprisingly the same protein accumulated in the mitochondria of a stable HeLa cell line, suggesting a differential localisation of CeHCF in mammalian cells. Furthermore, when overexpressed in transient transfection the CeHCF accumulated in both nuclear and mitochondrial compartments. We have refined the targeting determinants of CeHCF to the last 23 amino acids at the extreme C-terminus and show that they contain interdigitated amino acids involved in both nuclear and mitochondrial targeting. This novel targeting signal is sufficient to redirect HCF-2 into mitochondria. It can also be transferred to an unrelated protein, resulting in its targeting to both the mitochondrial and nuclear compartments.
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Affiliation(s)
- Ander Izeta
- Marie Curie Research Institute, The Chart, Oxted, Surrey, UK
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Azuara-Liceaga E, Sandoval M, Corona M, Gariglio P, López-Bayghen E. The human involucrin gene is transcriptionally repressed through a tissue-specific silencer element recognized by Oct-2. Biochem Biophys Res Commun 2004; 318:361-71. [PMID: 15120610 DOI: 10.1016/j.bbrc.2004.04.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2004] [Indexed: 11/16/2022]
Abstract
Involucrin is an important marker of epithelial differentiation which expression is upregulated just after basal cells are pushed into the suprabasal layer in stratified epithelia. Several transcription factors and regulatory elements had been described as responsible for turning on the gene. However, it is evident that in basal cell layer, additional mechanisms are involved in keeping the gene silent before the differentiation process starts. In this work, we located a potential transcriptional silencer in a 52bp sequence whose integrity is necessary for silencing the proximal enhancer promoter element (PEP) in multiplying keratinocytes. Octamer-binding sites were noticed in this fragment and the specific binding of Oct-2 transcription factor was detected. Oct-2 appears to be implicated in an epithelial-specific repression activity recorded only in keratinocytes and C33-A cell line. Overexpression of Oct-2 repressed the involucrin promoter activity in epithelial cells and in the presence of the silencer element.
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Affiliation(s)
- Elisa Azuara-Liceaga
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del I.P.N., Mexico D.F. 07000, Mexico
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15
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Blaud M, Vossen C, Joseph G, Alazard R, Erard M, Nieto L. Characteristic Patterns of N Oct-3 Binding to a Set of Neuronal Promoters. J Mol Biol 2004; 339:1049-58. [PMID: 15178247 DOI: 10.1016/j.jmb.2004.04.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 04/02/2004] [Accepted: 04/08/2004] [Indexed: 10/26/2022]
Abstract
N Oct-3, a neurospecific POU protein, homodimerizes in a non-cooperative fashion on the neuronal aromatic l-amino acid decarboxylase gene promoter and generates heterodimers with HNF-3beta. Several other neuronal gene promoters, the corticotropin releasing hormone and the aldolase C gene promoters also contain overlapping binding sites for N Oct-3 and HNF-3beta. We have demonstrated that N Oct-3 presents a non-cooperative homodimerization on these two additional targets and can also give rise to heterodimers with HNF-3beta. Surprisingly, despite the high degree of conservation of the respective POU subunits, the ubiquitous POU protein Oct-1 can only form monomers even in the presence of either N Oct-3 or HNF-3beta on these DNA targets. Our data indicate that this difference is correlated with the specific ability of a portion of the N Oct-3 linker to fold as an alpha-helix, a property shared by class III POU proteins. These results suggest that this novel binding pattern permits the heterodimerization of N Oct-3 and HNF-3beta on the neuronal promoters, which could be a key issue in the development of the nervous system and possibly tumors of neural origin.
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Affiliation(s)
- Magali Blaud
- Laboratoire de Pharmacologie et de Biologie Structurale, CNRS UPR 9062, 205, route de Narbonne, 31077 Toulouse Cedex, France
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16
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Zhang M, Genin A, Cron RQ. Overexpression of octamer transcription factors 1 or 2 alone has no effect on HIV-1 transcription in primary human CD4 T cells. Virology 2004; 321:323-31. [PMID: 15051391 DOI: 10.1016/j.virol.2004.01.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2003] [Revised: 01/14/2004] [Accepted: 01/14/2004] [Indexed: 11/16/2022]
Abstract
We explored the binding of octamer (Oct) transcription factors to the HIV-1 long terminal repeat (LTR) by gel shift assays and showed none of the previously identified four potential Oct binding sites bound Oct-1 or Oct-2. Overexpression of Oct-1 or Oct-2 had no effect on HIV-1 LTR activity in transiently transfected primary human CD4 T cells. Next, primary human CD4 T cells were co-transfected with a green fluorescent protein (GFP)-expression vector and an Oct-1 or Oct-2 expression plasmid. The transfected cells were stimulated for 2 days and then infected with the NL4-3 strain of HIV-1. After 3 days of infection, there were no differences in HIV-1 p24 supernatant levels. Apoptosis of infected or bystander cells overexpressing Oct-1 or Oct-2 compared to control was also unaffected. Our studies demonstrate that Oct-1 and Oct-2 fail to bind to the HIV-1 LTR and have no effect on HIV-1 transcription in primary human CD4 T cells.
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Affiliation(s)
- Mingce Zhang
- Division of Rheumatology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104-4318, USA
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17
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Belikov S, Astrand C, Holmqvist PH, Wrange O. Chromatin-mediated restriction of nuclear factor 1/CTF binding in a repressed and hormone-activated promoter in vivo. Mol Cell Biol 2004; 24:3036-47. [PMID: 15024090 PMCID: PMC371135 DOI: 10.1128/mcb.24.7.3036-3047.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mouse mammary tumor virus (MMTV) promoter-driven transcription is induced by glucocorticoid hormone via binding of the glucocorticoid receptor (GR). The MMTV promoter also harbors a binding site for nuclear factor 1 (NF1). NF1 and GR were expressed in Xenopus oocytes; this revealed GR-NF1 cooperativity both in terms of DNA binding and chromatin remodeling but not transcription. A fraction of NF1 sites were occupied in a hormone-dependent fashion, but a significant and NF1 concentration-dependent fraction were constitutively bound. Activation of the MMTV promoter resulted in an approximately 50-fold increase in the NF1 accessibility for its DNA site. The hormone-dependent component of NF1 binding was dissociated by addition of a GR antagonist; however, the antagonist RU486, which supports partial GR-DNA binding, also maintained partial NF1 binding. Hence GR-NF1 cooperativity is independent of agonist-driven chromatin remodeling. NF1 induced the formation of a micrococcal-nuclease-resistant protein-DNA complex containing the DNA segment from -185 to -55, the MMTV enhanceosome. Coexpression of NF1 and Oct1 resulted in a significant stimulation of hormone-induced MMTV transcription and also in increased basal transcription. We propose that hormone-independent NF1 binding may be involved in maintaining transcriptional competence and establishment of tissue-specific gene networks.
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Affiliation(s)
- Sergey Belikov
- Department of Cell and Molecular Biology, The Medical Nobel Institute, Karolinska Institutet, SE-17177 Stockholm, Sweden
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18
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Osborne AR, Zhang H, Fejer G, Palubin KM, Niesen MI, Blanck G. Oct-1 maintains an intermediate, stable state of HLA-DRA promoter repression in Rb-defective cells: an Oct-1-containing repressosome that prevents NF-Y binding to the HLA-DRA promoter. J Biol Chem 2004; 279:28911-9. [PMID: 15105429 DOI: 10.1074/jbc.m403118200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cell surface HLA-DR molecule binds foreign peptide antigen and forms an intercellular complex with the T cell receptor in the course of the development of an immune response against or immune tolerance to the antigen represented by the bound peptide. The HLA-DR molecule also functions as a receptor that mediates cell signaling pathways, including as yet poorly characterized pathway(s) leading to apoptosis. Expression of HLA-DR mRNA and protein is ordinarily inducible by interferon-gamma but is not inducible in tumor cells defective for the retinoblastoma tumor suppressor protein (Rb). In the case of the HLA-DRA gene, which encodes the HLA-DR heavy chain, previous work has indicated that this loss of inducibility is attributable to Oct-1 binding to the HLA-DRA promoter. In this report, we used Oct-1 antisense transformants to determine that Oct-1 represses the interferon-gamma response of the endogenous HLA-DRA gene. This determination is consistent with results from a chromatin immunoprecipitation assay, indicating that Oct-1 occupies the endogenous HLA-DRA promoter when the HLA-DRA promoter is inactive in Rb-defective cells but not when the promoter is converted to a previously defined, transcriptionally competent state, induced by treatment of the Rb-defective cells with the HDAC inhibitor, trichostatin A. In vitro DNA-protein binding analyses indicated that Oct-1 prevents HLA-DRA promoter activation by mediating the formation of a complex of proteins, termed DRAN (DRA negative), that blocks NF-Y access to the promoter.
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Affiliation(s)
- Aaron R Osborne
- Department of Biochemistry, College of Medicine, University of South Florida, Tampa, FL 33612, USA
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19
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Zhao FQ, Zheng Y, Dong B, Oka T. Cloning, genomic organization, expression, and effect on beta-casein promoter activity of a novel isoform of the mouse Oct-1 transcription factor. Gene 2004; 326:175-87. [PMID: 14729276 DOI: 10.1016/j.gene.2003.10.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ubiquitously expressed transcription factor Oct-1, a member of the POU domain factors, is involved in the regulation of expression of many tissue-specific and house-keeping genes. Multiple alternatively spliced isoforms of Oct-1 have been identified in human and mouse cells. The expression patterns of these isoforms and the analysis of their genomic organization and structure have suggested that the structural variation of Oct-1 isoforms may be important in conferring target and tissue specificity to its transcriptional activity. In this study, we have cloned and sequenced a new mouse Oct-1 isoform, named mOct-1Z. This novel isoform differs markedly at the C-terminus from the previously identified Oct-1 isoforms A, B, and C. It is generated by alternative splicing from the Oct-1 gene and its transcript exhibits a frameshift followed by an early stop codon, thus, its predicted protein has a distinct, much shorter C-terminal tail. However, this truncated isoform could still effectively bind to a consensus Oct-1 motif oligonucleotide and, like Oct-1B, activated the basal promoter activity of the mouse beta-casein gene. Oct-1Z is another ubiquitously expressed Oct-1 isoform, its transcript being detected in all mouse tissues examined, including the mammary gland, liver, lung, kidney, spleen, small intestine mucosa, uterus, and ovary.
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Affiliation(s)
- Feng-Qi Zhao
- Lactation and Mammary Gland Biology Group, Department of Animal Science, University of Vermont, Burlington, VT 05405, USA.
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20
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Abstract
Nitric oxide, generated by the inducible form of nitric oxide synthase (iNOS), is a potential mediator of cytokine-induced beta-cell dysfunction in type 1 diabetes mellitus. We have previously shown that cytokine-induced iNOS expression is cycloheximide (CHX) sensitive and requires nuclear factor-kappa B (NF-kappa B) activation. In the present study, we show that an octamer motif located 20 bp downstream of the proximal NF-kappa B binding site in the rat iNOS promoter is critical for IL-1 beta and interferon-gamma induction of promoter activity in rat primary beta-cells and insulin-producing RINm5F cells. In gel shift assays, the octamer motif bound constitutively the transcription factor Oct1. Neither Oct1 nor NF-kappa B binding activities were blocked by CHX, suggesting that other factor(s) synthesized in response to IL-1 beta contribute to iNOS promoter induction. The high mobility group (HMG)-I(Y) protein also bound the proximal iNOS promoter region. HMG-I(Y) binding was decreased in cells treated with CHX and HMG-I(Y) silencing by RNA interference reduced IL-1 beta-induced iNOS promoter activity. These results suggest that Oct1, NF-kappa B, and HMG-I(Y) cooperate for transactivation of the iNOS promoter in pancreatic beta-cells.
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Affiliation(s)
- Martine I Darville
- Laboratory of Experimental Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium.
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21
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Linnell J, Mott R, Field S, Kwiatkowski DP, Ragoussis J, Udalova IA. Quantitative high-throughput analysis of transcription factor binding specificities. Nucleic Acids Res 2004; 32:e44. [PMID: 14990752 PMCID: PMC390317 DOI: 10.1093/nar/gnh042] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a general high-throughput approach to accurately quantify DNA-protein interactions, which can facilitate the identification of functional genetic polymorphisms. The method tested here on two structurally distinct transcription factors (TFs), NF-kappaB and OCT-1, comprises three steps: (i) optimized selection of DNA variants to be tested experimentally, which we show is superior to selecting variants at random; (ii) a quantitative protein-DNA binding assay using microarray and surface plasmon resonance technologies; (iii) prediction of binding affinity for all DNA variants in the consensus space using a statistical model based on principal coordinates analysis. For the protein-DNA binding assay, we identified a polyacrylamide/ester glass activation chemistry which formed exclusive covalent bonds with 5'-amino-modified DNA duplexes and hindered non-specific electrostatic attachment of DNA. Full accessibility of the DNA duplexes attached to polyacrylamide-modified slides was confirmed by the high degree of data correlation with the electromobility shift assay (correlation coefficient 93%). This approach offers the potential for high-throughput determination of TF binding profiles and predicting the effects of single nucleotide polymorphisms on TF binding affinity. New DNA binding data for OCT-1 are presented.
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Affiliation(s)
- Jane Linnell
- Wellcome Trust Centre for Human Genetics, University of Oxford, 7 Roosevelt Drive, Oxford OX3 7BN, UK
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22
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Wang VEH, Schmidt T, Chen J, Sharp PA, Tantin D. Embryonic lethality, decreased erythropoiesis, and defective octamer-dependent promoter activation in Oct-1-deficient mice. Mol Cell Biol 2004; 24:1022-32. [PMID: 14729950 PMCID: PMC321444 DOI: 10.1128/mcb.24.3.1022-1032.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oct-1 is a sequence-specific DNA binding transcription factor that is believed to regulate a large group of tissue-specific and ubiquitous genes. Both Oct-1 and the related but tissue-restricted Oct-2 protein bind to a DNA sequence termed the octamer motif (5'-ATGCAAAT-3') with equal affinity in vitro. To address the role of Oct-1 in vivo, an Oct-1-deficient mouse strain was generated by gene targeting. Oct-1-deficient embryos died during gestation, frequently appeared anemic, and suffered from a lack of Ter-119-positive erythroid precursor cells. This defect was cell intrinsic. Fibroblasts derived from these embryos displayed a dramatic decrease in Oct-1 DNA binding activity and a lack of octamer-dependent promoter activity in transient transfection assays. Interestingly, several endogenous genes thought to be regulated by Oct-1 showed no change in expression. When crossed to Oct-2(+/-) animals, transheterozygotes were recovered at a very low frequency. These findings suggest a critical role for Oct-1 during development and a stringent gene dosage effect with Oct-2 in mediating postnatal survival.
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Affiliation(s)
- Victoria E H Wang
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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23
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Abstract
The POU domain transcription factors Oct-1 and Oct-2 interact with the octamer element, a motif conserved within Ig promoters and enhancers, and mediate transcription from the Ig loci. Inactivation of Oct-2 by gene targeting results in normal B cell development and Ig transcription. To study the role of Oct-1 in these processes, the lymphoid compartment of RAG-1(-/-) animals was reconstituted with Oct-1-deficient fetal liver hematopoietic cells. Recipient mice develop B cells with levels of surface Ig expression comparable with wild type, although at slightly reduced numbers. These B cells transcribe Ig normally, respond to antigenic stimulation, undergo class switching, and use a normal repertoire of light chain variable segments. However, recipient mice show slight reductions in serum IgM and IgA. Thus, the Oct-1 protein is dispensable for B cell development and Ig transcription.
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Affiliation(s)
- Victoria E H Wang
- Department of Biology and Center for Cancer Research and McGovern Institute, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA
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24
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Abstract
Expression of the herpes simplex virus (HSV) immediate early (IE) genes is regulated by a multiprotein complex that is assembled on the TAATGARAT enhancer core element. The complex contains the cellular POU domain protein Oct-1, the viral transactivator VP16, and the cellular cofactor host cell factor 1. The current model suggests that the assembly depends on recognition of the core element by Oct-1. Here, HSV infection of Oct-1-deficient mouse embryonic fibroblast cells demonstrates that Oct-1 is critical for IE gene expression at low multiplicities of infection (moi). However, the protein is not essential for IE gene expression at high moi, indicating that VP16-mediated transcriptional induction through other IE regulatory elements is also important. This induction depends, at least in part, on the GA-binding protein binding elements that are present in each IE enhancer domain. Surprisingly, whereas the viral IE genes are expressed after high moi infection of Oct-1-deficient cells, the assembly of viral replication factories is severely impaired, revealing a second critical role for Oct-1 in HSV replication. The results have implications for both the HSV lytic and latency-reactivation cycles.
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Affiliation(s)
- Mauricio L Nogueira
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 4-131, 4 Center Drive, Bethesda, MD 20892, USA
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25
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Abstract
Signal transducer and activator of transcription 5 (STAT5) is activated by numerous cytokines that control blood cell development. STAT5 was also shown to actively participate in leukemogenesis. Among the target genes involved in cell growth, STAT5 had been shown to activate cyclin D1 gene expression. We now show that thrombopoietin-dependent activation of the cyclin D1 promoter depends on the integrity of a new bipartite proximal element that specifically binds STAT5A and -B transcription factors. We demonstrate that the stable recruitment of STAT5 to this element in vitro requires the integrity of an adjacent octamer element that constitutively binds the ubiquitous POU homeodomain protein Oct-1. We observe that cytokine-activated STAT5 and Oct-1 form a unique complex with the cyclin D1 promoter sequence. We find that STAT5 interacts with Oct-1 in vivo, following activation by different cytokines in various cellular contexts. This interaction involves a small motif in the carboxy-terminal region of STAT5 which, remarkably, is similar to an Oct-1 POU-interacting motif present in two well-known partners of Oct-1, namely, OBF-1/Bob and SNAP190. Our data offer new insights into the transcriptional regulation of the key cell cycle regulator cyclin D1 and emphasize the active roles of both STAT5 and Oct-1 in this process.
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Affiliation(s)
- Sophie Magné
- Department of Hematology, Institut Cochin, INSERM U567, CNRS UMR 8104, Université René Descartes, 123 Boulevard Port-Royal, 75014 Paris, France
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26
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Abstract
In B cells, the Igh gene locus contains several DNase I-hypersensitive (hs) sites with enhancer activity. These include the 3' Igh enhancers, which are located downstream of the Calpha gene(s) in both mouse and human. In vivo experiments have implicated murine 3' enhancers, hs3B and/or hs4, in class switching and somatic hypermutation. We previously reported that murine hs4 was regulated by NF-kappaB, octamer binding proteins, and Pax5 (B cell-specific activator protein). In this study we report that human hs4 is regulated differently. EMSAs and Western analysis of normal B cells before and after stimulation with anti-IgM plus anti-CD40 showed the same complex binding pattern formed by NF-kappaB, Oct-1, and Oct-2 (but not by Pax5). A similar EMSA pattern was detected in mature human B cell lines (BL-2, Ramos, and HS-Sultan) and in diffuse large B cell lymphoma cell lines, although yin yang 1 protein (YY1) binding was also observed. We have confirmed the in vivo association of these transcription factors with hs4 in B cells by chromatin immunoprecipitation assays. The diffuse large B cell lymphoma cell lines had a distinctive slow-migrating complex containing YY1 associated with Rel-B. We have confirmed by endogenous coimmunoprecipitation an association of YY1 with Rel-B, but not with other NF-kappaB family members. Transient transfection assays showed robust hs4 enhancer activity in the mature B cell lines, which was dependent on synergistic interactions between NF-kappaB and octamer binding proteins. In addition, human hs4 enhancer activity required Oct-2 and correlated with expression of Oct coactivator from B cells (OCA-B).
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Affiliation(s)
- Manuel A Sepulveda
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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27
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Truong MJ, Delsart V, Bahr GM. Differentially expressed genes in HIV-1-infected macrophages following treatment with the virus-suppressive immunomodulator murabutide. Virus Res 2004; 99:25-33. [PMID: 14687943 DOI: 10.1016/j.virusres.2003.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The synthetic immunomodulator murabutide has been found to suppress human immunodeficiency virus type-1 (HIV-1) replication, in macrophages, through a regulated expression of cellular factors needed at different steps in the virus replication cycle. To identify cellular genes implicated in the murabutide-induced virus inhibition, we have carried out a differential display analysis on HIV-1-infected macrophages that were treated, or not, with murabutide. Sequencing of the differentially regulated cDNA bands and verification of the reproducibility of the murabutide effects, by reverse transcription-polymerase chain reaction or by Northern blotting, revealed an up-regulated expression of 21 genes and a down-regulation of seven others. The murabutide-regulated genes encoded proteins implicated in DNA binding, regulation of transcription, oxidative stress, metal binding, and other physiological functions. Six of the genes corresponded to unassigned/expressed sequence tags with yet unknown function. Among the genes which were up-regulated by murabutide and with established effects on inhibiting virus transcription, was the octamer binding factor 1 (Oct-1). We demonstrate the ability of murabutide to induce enhanced Oct-1 protein expression and DNA-binding activity in macrophages. Furthermore, our findings suggest the potential implication of additional transcription factors and metal-binding proteins in mediating the inhibitory effect of murabutide on virus transcription.
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Affiliation(s)
- Marie José Truong
- Laboratory of Molecular Immunology of Infection and Inflammation, Pasteur Institute in Lille, 1 Rue du Pr Calmette, BP 245, Lille Cedex 59019, France
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28
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Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infects a wide variety of insect species. A number of AcMNPV late expression factors that are involved in replication have been identified as playing a role in determining host specificity. Host cell factor-1, or HCF-1, was previously demonstrated to be essential for viral replication in Tn-368 cells. Here we demonstrate that HCF-1 is an early protein and localizes to the cell nucleus. Coprecipitation experiments revealed that HCF-1 interacts with itself but none of the other late expression factors required for replication in Tn-368 cells. HCF-1 mutants were constructed and utilized to search for the domains involved in HCF-1 biological function and oligomerization. Possible roles of HCF-1 in determining host specificity are discussed.
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Affiliation(s)
- K L Hefferon
- Cornell Research Foundation, Cornell University, Ithaca, NY 14850, USA.
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29
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Advani SJ, Durand LO, Weichselbaum RR, Roizman B. Oct-1 is posttranslationally modified and exhibits reduced capacity to bind cognate sites at late times after infection with herpes simplex virus 1. J Virol 2003; 77:11927-32. [PMID: 14581529 PMCID: PMC254286 DOI: 10.1128/jvi.77.22.11927-11932.2003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In herpes simplex virus 1-infected cells, a high level of alpha gene expression requires the transactivation of the genes by a complex containing the viral alpha transinducing factor (alphaTIF) and two cellular proteins. The latter two, HCF-1 and octamer binding protein Oct-1, are transcriptional factors regulated in a cell cycle-dependent manner. alphaTIF is a protein made late in infection but packaged with the virion to transactivate viral genes in newly infected cells. In light of the accumulation of large amounts of alphaTIF, the absence of alpha gene expression late in infection suggested the possibility that one or more transcriptional factors required for alpha gene expression is modified late in infection. Here we report that Oct-1 is posttranscriptionally modified late in infection, that the modification is mediated by the virus but does not involve viral protein kinases or cdc2 kinase activated by the virus late in infection, and that the modified Oct-1 has a reduced affinity for its cognate DNA site. These results are consistent with the hypothesis that modification of Oct-1 transcriptional factor could account at least in part for the shutoff of alpha gene expression late in infection.
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Affiliation(s)
- Sunil J Advani
- The Marjorie B. Kovler Viral Oncology Laboratories, The University of Chicago, Chicago, Illinois 60637, USA
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30
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Schild-Poulter C, Shih A, Yarymowich NC, Haché RJG. Down-regulation of histone H2B by DNA-dependent protein kinase in response to DNA damage through modulation of octamer transcription factor 1. Cancer Res 2003; 63:7197-205. [PMID: 14612514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Cells respond to double-stranded DNA breaks (DSBs) by pausing cell cycle progression to allow the repair machinery to restore genomic integrity. DNA-dependent protein kinase (DNA-PK), comprising a large catalytic subunit (DNA-PK(cs)) and the Ku antigen regulatory subunit (Ku70/Ku80), is activated in response to DSBs and is required for DNA repair through the nonhomologous end-joining pathway. Here we provide evidence that DNA-PK participates in altering specific gene expression in response to DNA damage by modulating the stability and transcriptional regulatory potential of the essential transcription factor octamer transcription factor 1 (Oct-1). Histone H2B and U2 RNA, whose expression are highly dependent on Oct-1, were strongly decreased in response to ionizing radiation in a DNA-PK-dependent manner, and Oct-1-dependent reporter gene transcription was repressed. Furthermore, Oct-1 phosphorylation in response to ionizing radiation increased in a DNA-PK-dependent manner. Paradoxically, down-regulation of transactivation correlated with the rapid DNA-PK-dependent stabilization of Oct-1. Stabilization of Oct-1 was dependent on the NH(2)-terminal region of Oct-1, which contains a transcriptional activation domain and which was phosphorylated by DNA-PK in vitro. These results suggest a mechanism for the regulation of Oct-1 in response to DNA damage through specific phosphorylation within the NH(2)-terminal transcriptional regulatory domain.
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Affiliation(s)
- Caroline Schild-Poulter
- Department of Medicine, University of Ottawa, The Ottawa Health Research Institute, 725 Parkdale Avenue, Ottawa, Ontario K1Y 4E9, Canada.
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31
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Hirose T, Sowa Y, Takahashi S, Saito S, Yasuda C, Shindo N, Furuichi K, Sakai T. p53-independent induction of Gadd45 by histone deacetylase inhibitor: coordinate regulation by transcription factors Oct-1 and NF-Y. Oncogene 2003; 22:7762-73. [PMID: 14586402 DOI: 10.1038/sj.onc.1207091] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2002] [Revised: 08/06/2003] [Accepted: 08/07/2003] [Indexed: 11/09/2022]
Abstract
Histone deacetylase (HDAC) inhibitors cause growth arrest at the G1 and/or G2/M phases, and induce differentiation and/or apoptosis in a wide variety of tumour cells. The growth arrest at G1 phase by HDAC inhibitors is thought to be highly dependent on the upregulation of p21/WAF1, but the precise mechanism by which HDAC inhibitors cause G2/M arrest or apoptosis in tumour cells is unknown. Gadd45 causes cell cycle arrest at the G2/M phase transition and participates in genotoxic stress-induced apoptosis. We show here that it is also induced by a typical HDAC inhibitor, trichostatin A (TSA), through its promoter, in a p53-independent manner. To identify the mechanism of activation of the gadd45 promoter, we performed luciferase reporter analyses and electrophoretic mobility shift assays. These revealed that both the Oct-1 and CCAAT sites are needed for the full activation by TSA. We also found that the transcription factors Oct-1 and NF-Y specifically bind to each site. Thus, HDAC inhibitors can induce Gadd45 through its promoter without the need for functional p53, and both the Oct-1 and NF-Y concertedly participate in TSA-induced activation of the gadd45 promoter.
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Affiliation(s)
- Tohru Hirose
- Department of Preventive Medicine, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan
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32
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Abstract
HCF-1 is a transcriptional cofactor required for activation of herpes simplex virus immediate-early genes by VP16 as well as less clearly defined roles in cell proliferation, cytokinesis, and spliceosome formation. It is expressed as a large precursor that undergoes proteolysis to yield two subunits that remain stably associated. VP16 uses a degenerate 4-amino acid sequence, known as the HCF-binding motif, to bind to a six-bladed beta-propeller domain at the N terminus of HCF-1. Functional HCF-binding motifs are also found in LZIP and Zhangfei, two cellular bZIP transcription factors of unknown function. Here we show that the HCF-binding motif occurs in a wide spectrum of DNA-binding proteins and transcriptional cofactors. Three well characterized examples were further analyzed for their ability to use HCF-1 as a coactivator. Krox20, a zinc finger transcription factor required for Schwann cell differentiation, and E2F4, a cell cycle regulator, showed a strong requirement for functional HCF-1 to activate transcription. In contrast, activation by estrogen receptor-alpha did not display HCF dependence. In Krox20, the HCF-binding motif lies within the N-terminal activation domain and mutation of this sequence diminishes both transactivation and association with the HCF-1 beta-propeller. The activation domain in the C-terminal subunit of HCF-1 contributes to activation by Krox20, possibly through recruitment of p300. These results suggest that HCF-1 is recruited by many different classes of cellular transcription factors and is therefore likely to be required for a variety of cellular processes including cell cycle progression and development.
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Affiliation(s)
| | - Angus C. Wilson
- To whom correspondence should be addressed: Dept. of Microbiology, 550 First Ave., New York, NY 10016. Tel.: 212-263-0206; Fax: 212-263-8276;
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33
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Fumoto M, Okimura Y, Sakagami Y, Iguchi G, Kishimoto M, Takahashi Y, Kaji H, Chihara K. Cloning of a protein binding to the most proximal Pit-1 binding element of prolactin gene from human pituitary cDNA library. Mol Cell Endocrinol 2003; 207:31-8. [PMID: 12972181 DOI: 10.1016/s0303-7207(03)00207-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A human pituitary cDNA library was screened using a yeast one-hybrid system to find a factor binding Pit-1 binding elements in the PRL gene other than Pit-1. Beside colonies containing Pit-1 or Oct-1 cDNA, three colonies contained mPOU cDNA, a member of the POU protein family. Immunohistochemical analysis showed mPOU-like immunoreactivity was present in human PRL-producing pituitary tumors but not in non-functioning pituitary tumors. Mobility shift analysis revealed that mPOU bound to Pit-1 binding elements of the PRL gene, 1P and 3P. mPOU activated the expression of 0.6 k PRL and 7x1P reporter genes in the presence of Pit-1 and cAMP, although it did not enhance Pit-1-induced expression of 7x3P reporter gene. These findings suggest that mPOU is involved in the activation of the PRL gene by cAMP through 1P in the presence of Pit-1.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Binding Sites
- COS Cells
- Calcium/metabolism
- Chlorocebus aethiops
- Cloning, Molecular
- Cyclic AMP/analogs & derivatives
- Cyclic AMP/pharmacology
- DNA, Complementary/chemistry
- DNA, Complementary/isolation & purification
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Electrophoretic Mobility Shift Assay
- Gene Expression Regulation/drug effects
- Gene Library
- Genes, Reporter/genetics
- Genetic Vectors/administration & dosage
- Genetic Vectors/genetics
- Host Cell Factor C1
- Humans
- Immunohistochemistry
- Mutation
- Octamer Transcription Factor-1
- POU Domain Factors
- Pituitary Gland/metabolism
- Prolactin/genetics
- Promoter Regions, Genetic/genetics
- Protein Binding
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Repetitive Sequences, Nucleic Acid/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Thionucleotides/pharmacology
- Transcription Factor Pit-1
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transfection
- Two-Hybrid System Techniques
- Yeasts/genetics
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Affiliation(s)
- Mariko Fumoto
- Division of Endocrinology/Metabolism, Neurology and Hematology/Oncology, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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34
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Sytina EV, Pankratova EV. [Oct-1 transcription factor--plasticity and polyfunctionality]. Mol Biol (Mosk) 2003; 37:755-67. [PMID: 14593912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The problem considered is how one transcription factor controls numerous processes in the organism. The mechanisms determining the multiplicity of Oct-1 functions are described.
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Affiliation(s)
- E V Sytina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991 Russia
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35
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Bruemmer D, Yin F, Liu J, Berger JP, Sakai T, Blaschke F, Fleck E, Van Herle AJ, Forman BM, Law RE. Regulation of the growth arrest and DNA damage-inducible gene 45 (GADD45) by peroxisome proliferator-activated receptor gamma in vascular smooth muscle cells. Circ Res 2003; 93:e38-47. [PMID: 12881480 DOI: 10.1161/01.res.0000088344.15288.e6] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Peroxisome proliferator-activated receptor (PPAR) gamma is activated by thiazolidinediones (TZDs), widely used as insulin-sensitizing agents for the treatment of type 2 diabetes. TZDs have been shown to induce apoptosis in a variety of mammalian cells. In vascular smooth muscle cells (VSMCs), proliferation and apoptosis may be competing processes during the formation of restenotic and atherosclerotic lesions. The precise molecular mechanisms by which TZDs induce apoptosis in VSMCs, however, remain unclear. In the present study, we demonstrate that the TZDs rosiglitazone (RSG), troglitazone (TRO), and a novel non-TZD partial PPARgamma agonist (nTZDpa) induce caspase-mediated apoptosis of human coronary VSMCs. Induction of VSMC apoptosis correlated closely with an upregulation of growth arrest and DNA damage-inducible gene 45 (GADD45) mRNA expression and transcription, a well-recognized modulator of cell cycle arrest and apoptosis. Using adenoviral-mediated overexpression of a constitutively active PPARgamma mutant and the irreversible PPARgamma antagonist GW9662, we provide evidence that PPARgamma ligands induce caspase-mediated apoptosis and GADD45 expression through a receptor-dependent pathway. Deletion analysis of the GADD45 promoter revealed that a 153-bp region between -234 and -81 bp proximal to the transcription start site, containing an Oct-1 element, was crucial for the PPARgamma ligand-mediated induction of the GADD45 promoter. PPARgamma activation induced Oct-1 protein expression and DNA binding and stimulated activity of a reporter plasmid driven by multiple Oct-1 elements. These findings suggest that activation of PPARgamma can lead to apoptosis and growth arrest in VSMCs, at least in part, by inducing Oct-1-mediated transcription of GADD45. The full text of this article is available online at http://www.circresaha.org.
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MESH Headings
- Amino Acid Chloromethyl Ketones/pharmacology
- Apoptosis/drug effects
- Binding Sites/genetics
- Blotting, Northern
- Caspase Inhibitors
- Cell Division/drug effects
- Cells, Cultured
- Chromans/pharmacology
- Cysteine Proteinase Inhibitors/pharmacology
- DNA Damage
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Dose-Response Relationship, Drug
- Gene Expression Regulation/drug effects
- Host Cell Factor C1
- Humans
- Intracellular Signaling Peptides and Proteins
- Luciferases/genetics
- Luciferases/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Mutation
- Octamer Transcription Factor-1
- Promoter Regions, Genetic/genetics
- Protein Binding
- Proteins/genetics
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/physiology
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Rosiglitazone
- Thiazoles/pharmacology
- Thiazolidinediones
- Transcription Factors/agonists
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription Factors/physiology
- Transcription, Genetic/drug effects
- Troglitazone
- GADD45 Proteins
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Affiliation(s)
- Dennis Bruemmer
- Division of Endocrinology, Diabetes and Hypertension and The Gonda (Goldschmied) Diabetes Center, David Geffen School of Medicine, University of California, Los Angeles, Calif 90095, USA
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36
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Mayer CM, Cai F, Cui H, Gillespie JMA, MacMillan M, Belsham DD. Analysis of a repressor region in the human neuropeptide Y gene that binds Oct-1 and Pbx-1 in GT1-7 neurons. Biochem Biophys Res Commun 2003; 307:847-54. [PMID: 12878188 DOI: 10.1016/s0006-291x(03)01289-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The mechanisms dictating the developmental expression of individual neuropeptides within the hypothalamus have not yet been elucidated. In this paper we have studied the cis-acting elements involved in the repression of neuropeptide Y (NPY) gene expression in a gonadotropin-releasing hormone (GnRH) neuronal cell model, GT1-7 cells. Using transient transfection of the human NPY 5(') regulatory region into the GT1-7 neurons, we have found a repressor region located between -867 and -1078. DNase I footprint analysis of this region revealed three specific protein binding elements. Further analysis of the region between -942 and -922bp using electrophoretic mobility shift assays revealed that four different transcription factor-DNA complexes form with GT1-7 nuclear proteins, whereas only three complexes are detected using baby hamster kidney (BHK) cell nuclear extract. Mutation of the consensus binding sequence abolishes all complex formation on the -924/-922 oligonucleotide. Antibody supershift assays revealed that Oct-1 and Pbx-1 antibodies were able to eliminate the appearance of two specific complexes. Therefore we suggest that this region may be important for transcriptional repression of the NPY gene in a heterologous cell model, through complex, coordinate protein-protein interactions.
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Affiliation(s)
- Christopher M Mayer
- Department of Physiology, University of Toronto, Medical Sciences Building 3247A, 1 King's College Circle, Toronto, Ont., Canada M5S 1A8
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37
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Abstract
The U3 region of the human endogenous retrovirus W long terminal repeat (HERV-W LTR) contains several putative regulatory sequences that might not only regulate transcription of viral genes but also influence the expression of neighbouring cellular genes. In this study, we analysed the U3 region in detail in order to understand the transcriptional regulatory mechanism of HERV-W. Two transcription factor (TF) binding sites for Oct-1 and C/EBP were important as a silencer and an enhancer, respectively, for transcriptional regulation. Furthermore, it was possible to divide the HERV-W LTR isolates into two groups depending on their promoter strength, which might be determined by the integrity of the two TF binding sites. However, neither the Oct-1 binding site nor the CAAT-box was required for the cell type-specific activity of the HERV-W LTR. Instead, the 3' terminus of U3 from 191 to 260, which includes a TATA box, was sufficient for specificity, suggesting that the efficiency of assembly of basic transcription machinery at the TATA box of HERV-W LTR might determine the cell type specificity.
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Affiliation(s)
- Woo Jung Lee
- Department of Microbiology, College of Natural Sciences, Pusan National University, Pusan 609-735, South Korea
| | - Hyun Jin Kwun
- Department of Microbiology, College of Natural Sciences, Pusan National University, Pusan 609-735, South Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Sciences, Pusan National University, Pusan 609-735, South Korea
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38
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Abstract
Histone gene expression in mammalian cells is codependent upon the Oct-1 transcription factor and its cognate, OCA-S coactivator complex. Surprisingly, GADPH plays an essential role in the OCA-S complex and confers redox dependence upon the in vitro transcription of histone genes.
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Affiliation(s)
- Steve McKnight
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
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39
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Abstract
We have isolated and functionally characterized a multicomponent Oct-1 coactivator, OCA-S which is essential for S phase-dependent histone H2B transcription. The p38 component of OCA-S binds directly to Oct-1, exhibits potent transactivation potential, is selectively recruited to the H2B promoter in S phase, and is essential for S phase-specific H2B transcription in vivo and in vitro. Surprisingly, p38 represents a nuclear form of glyceraldehyde-3-phosphate dehydrogenase, and binding to Oct-1, as well as OCA-S function, is stimulated by NAD(+) but inhibited by NADH. OCA-S also interacts with NPAT, a cyclin E/cdk2 substrate that is broadly involved in histone gene transcription. These studies thus link the H2B transcriptional machinery to cell cycle regulators, and possibly to cellular metabolic state (redox status), and set the stage for studies of the underlying mechanisms and the basis for coordinated histone gene expression and coupling to DNA replication.
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Affiliation(s)
- Lei Zheng
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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40
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Abstract
The ubiquitous transcription factor Oct-1 is a member of the POU domain family of regulatory proteins. Target genes controlled by Oct-1 include housekeeping genes, e.g. the genes encoding histon H2B or snRNAs, as well as tissue-specific genes, e.g. the genes encoding the light and heavy chains of immunoglobulines, some interleukins, and others. Oct-1 pre-mRNA may be spliced in several ways, resulting in production of several protein isoforms that may differ functionally. The 5'-end of the Oct-1 gene contains two exons-exon 1U and exon 1L that alternatively present in Oct-1 mRNA. We studied regulation of transcription of the Oct-1 gene using reporter gene assays of promoter-luciferase gene-constructs. It was shown that transcription of the Oct-1 gene is regulated by two promoters located upstream of the exon 1U and upstream of the exon 1L. The promoter located upstream of the exon 1U contains G/C-rich sequences and multiple Sp1 sites, while the promoter located upstream of the exon 1L contains A/T-rich motifs and autoregulation-related cis-elements: two octamer sites ATGCAAAT, two octamer related sites and multiple TAAT-core sites. Exons 1U and 1L in the human OTF-1 locus encoding the Oct-1 gene are located at the distance of 108 kbp. In the murine locus otf-1 the distance between exons 1U and 1L is 67 kbp. We suggest that the two promoters can differ functionally.
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Affiliation(s)
- Elizaveta V Pankratova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str., 32, Moscow, 119991, Russia.
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41
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Georgel PT, Fletcher TM, Hager GL, Hansen JC. Formation of higher-order secondary and tertiary chromatin structures by genomic mouse mammary tumor virus promoters. Genes Dev 2003; 17:1617-29. [PMID: 12842912 PMCID: PMC196134 DOI: 10.1101/gad.1097603] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [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] [Indexed: 11/25/2022]
Abstract
Agarose multigel electrophoresis has been used to characterize the structural features of isolated genomic mouse mammary tumor virus (MMTV) promoters. The mouse 3134 cells used for these studies contain approximately 200 stably integrated tandem repeats of a 2.4-kb MMTV promoter fragment. Inactive, basally active, and hormonally activated genomic promoters were liberated by restriction digestion of isolated nuclei, recovered in low-salt nuclear extracts, and electrophoresed in multigels consisting of nine individual agarose running gels. Specific bands were detected and characterized by Southern and Western blotting. We find that transcriptionally inactive promoters contain TBP and high levels of histone H1, and are present to varying extents in both untreated and dexamethasone (DEX)-treated 3134 cells. In contrast, the basally active promoter, present in untreated cells, is bound to RNA Pol II, TBP, and Oct1, contains acetylated H3 tail domains, and is depleted of histone H1. The DEX-activated promoter possessed similar composition as the basal promoter, but also contains stably bound Brg1. Strikingly, all forms of the MMTV promoter condense into higher-order secondary and/or tertiary chromatin structures in vitro in the presence of Mg2+. Thus, genomic MMTV promoter chromatin retains the ability to form classical higher-order structures under physiological salt conditions, even after dissociation of H1 and binding of several transcription factors and multiprotein complexes. These results suggest that transcriptionally active eukaryotic promoters may function in a locally folded chromatin environment in vivo.
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Affiliation(s)
- Philippe T Georgel
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA
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42
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Weber M, Sydlik C, Quirling M, Nothdurfter C, Zwergal A, Heiss P, Bell S, Neumeier D, Ziegler-Heitbrock HWL, Brand K. Transcriptional inhibition of interleukin-8 expression in tumor necrosis factor-tolerant cells: evidence for involvement of C/EBP beta. J Biol Chem 2003; 278:23586-93. [PMID: 12707271 DOI: 10.1074/jbc.m211646200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
There is some evidence that the potent cytokine tumor necrosis factor (TNF) is able to induce tolerance after repeated stimulation of cells. To investigate the molecular mechanisms mediating this phenomenon, the expression of interleukin-8 (IL-8), which is regulated by transcription factors NF-kappaB and C/EBPbeta, was monitored under TNF tolerance conditions. Pretreatment of monocytic cells for 72 h with low TNF doses inhibited TNF-induced (restimulation with a high dose) IL-8 promoter-dependent transcription as well as IL-8 production. Under these conditions neither activation of NF-kappaB nor IkappaB proteolysis was affected after TNF re-stimulation, albeit a slightly reduced IkappaB-alpha level was found in the TNF pretreated but not re-stimulated sample. Remarkably, in tolerant cells an increased binding of C/EBPbeta to its IL-8 promoter-specific DNA motif as well as an elevated association of C/EBPbeta protein with p65-containing NF-kappaB complexes was observed. Finally, overexpression of C/EBPbeta, but not p65 or Oct-1, markedly prevented TNF-induced IL-8 promoter-dependent transcription. Taken together, these data indicate that the expression of IL-8 is inhibited at the transcriptional level in TNF-tolerant cells and C/EBPbeta is involved under these conditions in mediating the negative-regulatory effects, a mechanism that may play a role in inflammatory processes such as sepsis.
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Affiliation(s)
- Marion Weber
- Institute of Clinical Chemistry and Pathobiochemistry, Klinikum rechts der Isar, Technische Universität, 81675 München, Germany
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43
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Schaffer A, Kim EC, Wu X, Zan H, Testoni L, Salamon S, Cerutti A, Casali P. Selective inhibition of class switching to IgG and IgE by recruitment of the HoxC4 and Oct-1 homeodomain proteins and Ku70/Ku86 to newly identified ATTT cis-elements. J Biol Chem 2003; 278:23141-50. [PMID: 12672812 DOI: 10.1074/jbc.m212952200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Immunoglobulin (Ig) class switching is central to the maturation of the antibody response as IgG, IgA, and IgE are endowed with more diverse biological effector functions than IgM. It is induced upon engagement of CD40 on B lymphocytes by CD40L expressed by activated CD4+ T cells and exposure of B cells to T cell-secreted cytokines including interleukin-4 and transforming growth factor-beta. It begins with germ line IH-CH transcription and unfolds through class switch DNA recombination (CSR). We show here that the HoxC4 and Oct-1 homeodomain proteins together with the Ku70/Ku86 heterodimer bind as a complex to newly identified switch (S) regulatory ATTT elements (SREs) in the Igamma and Iepsilon promoters and downstream regions to dampen basal germ line Igamma-Cgamma and Iepsilon-Cepsilon transcriptions and repress CSR to Cgamma and Cepsilon. This mechanism is inactive in the Calpha1/Calpha2 loci because of the lack of SREs in the Ialpha1/Ialpha2 promoters. Accordingly, in resting human IgM+IgD+ B cells, HoxC4, Oct-1, and Ku70/Ku86 can be readily identified as bound to the Igamma and Iepsilon promoters but not the Ialpha1/Ialpha2 promoters. CD40 signaling dissociates the HoxC4.Oct-1. Ku complex from the Igamma and Iepsilon promoter SREs, thereby relieving the IH-CH transcriptional repression and allowing CSR to unfold. Dissociation of HoxC4.Oct-1. Ku from DNA is hampered by CD153 engagement, a CD40-signaling inhibitor. Thus, these findings outline a HoxC4.Oct-1. Ku-dependent mechanism of selective regulation of class switching to IgG and IgE and further suggest distinct co-evolution and shared CSR activation pathways in the Cgamma and Cepsilon as opposed to the Calpha1/Calpha2 loci.
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Affiliation(s)
- András Schaffer
- Division of Molecular Immunology, Department of Pathology and Laboratory Medicine, Joan and Sanford I. Weill Medical College, Cornell University, New York, New York 10021, USA
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44
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Abstract
Replication of the adenovirus genome is catalysed by adenovirus DNA polymerase in which the adenovirus preterminal protein acts as a protein primer. DNA polymerase and preterminal protein form a heterodimer which, in the presence of the cellular transcription factors NFI/CTFI and NFIII/Oct-1, binds to the origin of DNA replication. DNA replication is initiated by DNA polymerase mediated transfer of dCMP onto preterminal protein. Further DNA synthesis is catalysed by DNA polymerase in a strand displacement mechanism which also requires adenovirus DNA binding protein. Here, we discuss the role of individual proteins in this process as revealed by biochemical analysis, mutagenesis and molecular modelling.
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Affiliation(s)
- H Liu
- Centre for Biomolecular Science, Biomolecular Science Building, The University of St. Andrews, North Haugh, St. Andrews, KY16 9ST, UK
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45
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Mizuno D, Takahashi Y, Hiroi T, Imaoka S, Kamataki T, Funae Y. A novel transcriptional element which regulates expression of the CYP2D4 gene by Oct-1 and YY-1 binding. Biochim Biophys Acta 2003; 1627:121-8. [PMID: 12818430 DOI: 10.1016/s0167-4781(03)00085-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We first identified the transcriptional regulatory element of the CYP2D4 gene. CYP2D4 is of interest in brain pharmacology and physiology because this enzyme can be involved in the metabolism of endogenous and exogenous compounds, which act on the central nervous system. Transfection studies using a series of the CYP2D4 promoter luciferase constructs identified the transcriptional element of CYP2D4 in the sequence between nucleotides -116 and -90 (named the neural expression regulatory element, NERE). The nucleotide sequence of NERE was specific for the CYP2D4 gene. Within this region, two nuclear factor-binding sequences, Oct-1 and YY-1, were present. Oct-1 acts as the activator of the CYP2D4. The core sequence of the YY-1 binding motif partially overlapped that of the Oct-1 binding motif. YY-1 may act as the repressor of CYP2D4, which interferes with Oct-1 activation by its binding to NERE. We concluded that a novel transcriptional regulatory element NERE specifically regulates the expression of the CYP2D4. This regulation system may be involved in the unique distribution of this isoform, such as the expression in the brain.
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Affiliation(s)
- Dai Mizuno
- Department of Chemical Biology, Osaka City University Medical School, 1-4-3, Asahimachi, Abeno-ku, Osaka 545-8585, Japan
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46
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Abstract
Adenovirus (Ad) type 5 DNA packaging is initiated in a polar fashion from the left end of the genome. The packaging process is dependent upon the cis-acting packaging domain located between nucleotides 194 and 380. Seven A/T-rich repeats have been identified within this domain that direct packaging. A1, A2, A5, and A6 are the most important repeats functionally and share a bipartite sequence motif. Several lines of evidence suggest that there is a limiting trans-acting factor(s) that plays a role in packaging. Two cellular activities that bind to minimal packaging domains in vitro have been previously identified. These binding activities are P complex, an uncharacterized protein(s), and chicken ovalbumin upstream promoter transcription factor (COUP-TF). In this work, we report that a third cellular protein, octamer-1 protein (Oct-1), binds to minimal packaging domains. In vitro binding analyses and in vivo packaging assays were used to examine the relevance of these DNA binding activities to Ad DNA packaging. The results of these experiments reveal that COUP-TF and Oct-1 binding does not play a functional role in Ad packaging, whereas P-complex binding directly correlates with packaging function. We demonstrate that P complex contains the cellular protein CCAAT displacement protein (CDP) and that full-length CDP is found in purified virus particles. In addition to cellular factors, previous evidence indicates that viral factors play a role in the initiation of viral DNA packaging. We propose that CDP, in conjunction with one or more viral proteins, binds to the packaging sequences of Ad to initiate the encapsidation process.
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Affiliation(s)
- Ece Erturk
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, New York 11794, USA
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47
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Abstract
When herpes simplex virus (HSV) infects human cells, it is able to enter two modes of infection: lytic and latent. A key activator of lytic infection is a virion protein called VP16, which, upon infection of a permissive cell, forms a transcriptional regulatory complex with two cellular proteins - the POU-domain transcription factor Oct-1 and the cell-proliferation factor HCF-1 - to activate transcription of the first set of expressed viral genes. This regulatory complex, called the VP16-induced complex, reveals mechanisms of combinatorial control of transcription. The activities of Oct-1 and HCF-1 - two important regulators of cellular gene expression and proliferation - illuminate strategies by which HSV might coexist with its host.
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48
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Abstract
HCF-1 is a highly conserved and abundant chromatin-associated host cell factor required for transcriptional activation of herpes simplex virus immediate-early genes by the virion protein VP16. HCF-1 exists as a heterodimeric complex of associated N- (HCF-1(N)) and C- (HCF-1(C)) terminal subunits that result from proteolytic processing of a precursor protein. We have used small-interfering RNA (siRNA) to inactivate HCF-1 in an array of normal and transformed mammalian cells to identify its cellular functions. Our results show that HCF-1 is a broadly acting regulator of two stages of the cell cycle: exit from mitosis, where it ensures proper cytokinesis, and passage through the G(1) phase, where it promotes cell cycle progression. Proteolytic processing is necessary to separate and ensure these two HCF-1 activities, which are performed by separate HCF-1 subunits: the HCF-1(N) subunit promotes passage through the G(1) phase whereas the HCF-1(C) subunit is involved in proper exit from mitosis. These results suggest that HCF-1 links the regulation of exit from mitosis and the G(1) phase of cell growth, possibly to coordinate the reactivation of gene expression after mitosis.
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Affiliation(s)
- Eric Julien
- Cold Spring Harbor Laboratory, NY 11724, USA
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Liu M, Leibowitz JL, Clark DA, Mendicino M, Ning Q, Ding JW, D'Abreo C, Fung L, Marsden PA, Levy GA. Gene transcription of fgl2 in endothelial cells is controlled by Ets-1 and Oct-1 and requires the presence of both Sp1 and Sp3. Eur J Biochem 2003; 270:2274-86. [PMID: 12752447 DOI: 10.1046/j.1432-1033.2003.03595.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immune coagulant fgl2/fibroleukin has been previously shown to play a pivotal role in the pathogenesis of murine and human fulminant hepatitis and fetal loss syndrome. Constitutive expression of fgl2 transcripts at low levels are seen in cytotoxic T cells, endothelial, intestinal and trophoblast cells, while specific factors (such as virus and cytokines) are required to induce high levels of fgl2 expression in other cell types including monocytes/macrophages. To address the transcriptional mechanisms that regulate constitutive expression of fgl2, murine genomic clones were characterized and the transcription start site was defined by 5'-RACE and primer extension. A comprehensive assessment of basal fgl2 promoter activity in murine vascular endothelial cells defined a minimal 119 bp region responsible for constitutive fgl2 transcription. A complex positive regulatory domain (PRD) spanning a 39-bp sequence from -87 to -49 (relative to the transcription start site) was identified. Electrophoretic mobility shift assay studies in vascular endothelial cells revealed that the nucleoprotein complexes that form on this positive regulatory domain (PRD) contain Sp1/Sp3 family members, Oct-1, and Ets-1. Heterologous expression studies in Drosophila Schneider cells confirmed that the constitutive expression of this gene is controlled by Ets-1 and requires the presence both of the Sp1 and Sp3 transcription factors. The presence of this complex multicomponent PRD in the fgl2 proximal promoter is consistent with the observation that, in vivo, fgl2 expression is tightly regulated. Moreover, viral induced fgl2 expression also requires the presence of this PRD. These results clearly demonstrate that multiple cis DNA elements in a clustered region work cooperatively to regulate constitutive fgl2 expression and interact with inducible elements to regulate viral-induced fgl2 expression in endothelial cells.
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Affiliation(s)
- Mingfeng Liu
- Multi Organ Transplant Program, Toronto General Hospital and The University of Toronto, Canada
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Akizawa Y, Nishiyama C, Hasegawa M, Maeda K, Nakahata T, Okumura K, Ra C, Ogawa H. Regulation of human FcepsilonRI beta chain gene expression by Oct-1. Int Immunol 2003; 15:549-56. [PMID: 12697656 DOI: 10.1093/intimm/dxg055] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The beta chain, a component of the high-affinity receptor for IgE (FcepsilonRI), plays an important role in IgE-mediated allergic reaction. The beta chain accelerates the function of FcepsilonRI by amplification of its surface expression and of signal transduction in effector cells such as mast cells and basophils. Two regulatory regions, +60/+66 and +70/+76, for the human beta chain gene that are required for the cell-type-specific transcriptional activation were identified by transient reporter assay. Electrophoretic mobility shift assay demonstrated that Oct-1 binds both the regions, among which the +70/+76 Oct-1 motif was critical for the transactivation of the beta promoter responsive to Oct-1 overexpression. Regulation of beta chain gene expression is discussed.
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Affiliation(s)
- Yushiro Akizawa
- Atopy (Allergy) Research Center, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
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