1
|
Viral infection upregulates myostatin promoter activity in orange-spotted grouper (Epinephelus coioides). PLoS One 2017; 12:e0186506. [PMID: 29036192 PMCID: PMC5643063 DOI: 10.1371/journal.pone.0186506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 10/03/2017] [Indexed: 11/24/2022] Open
Abstract
Myostatin is a negative regulator of myogenesis and has been suggested to be an important factor in the development of muscle wasting during viral infection. The objective of this study was to characterize the main regulatory element of the grouper myostatin promoter and to study changes in promoter activity due to viral stimulation. In vitro and in vivo experiments indicated that the E-box E6 is a positive cis-and trans-regulation motif, and an essential binding site for MyoD. In contrast, the E-box E5 is a dominant negative cis-regulatory. The characteristics of grouper myostatin promoter are similar in regulation of muscle growth to that of other species, but mainly through specific regulatory elements. According to these results, we conducted a study to investigate the effect of viral infection on myostatin promoter activity and its regulation. The nervous necrosis virus (NNV) treatment significantly induced myostatin promoter activity. The present study is the first report describing that specific myostatin motifs regulate promoter activity and response to viral infection.
Collapse
|
2
|
17β-Estradiol-induced interaction of estrogen receptor α and human atrial essential myosin light chain modulates cardiac contractile function. Basic Res Cardiol 2016; 112:1. [DOI: 10.1007/s00395-016-0590-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/02/2016] [Indexed: 11/29/2022]
|
3
|
Almeida CF, Martins PC, Vainzof M. Comparative transcriptome analysis of muscular dystrophy models Large(myd), Dmd(mdx)/Large(myd) and Dmd(mdx): what makes them different? Eur J Hum Genet 2016; 24:1301-9. [PMID: 26932192 DOI: 10.1038/ejhg.2016.16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 01/26/2016] [Accepted: 02/01/2016] [Indexed: 11/09/2022] Open
Abstract
Muscular dystrophies (MD) are a clinically and genetically heterogeneous group of Mendelian diseases. The underlying pathophysiology and phenotypic variability in each form are much more complex, suggesting the involvement of many other genes. Thus, here we studied the whole genome expression profile in muscles from three mice models for MD, at different time points: Dmd(mdx) (mutation in dystrophin gene), Large(myd-/-) (mutation in Large) and Dmd(mdx)/Large(myd-/-) (both mutations). The identification of altered biological functions can contribute to understand diseases and to find prognostic biomarkers and points for therapeutic intervention. We identified a substantial number of differentially expressed genes (DEGs) in each model, reflecting diseases' complexity. The main biological process affected in the three strains was immune system, accounting for the majority of enriched functional categories, followed by degeneration/regeneration and extracellular matrix remodeling processes. The most notable differences were in 21-day-old Dmd(mdx), with a high proportion of DEGs related to its regenerative capacity. A higher number of positive embryonic myosin heavy chain (eMyHC) fibers confirmed this. The new Dmd(mdx)/Large(myd-/-) model did not show a highly different transcriptome from the parental lineages, with a profile closer to Large(myd-/-), but not bearing the same regenerative potential as Dmd(mdx). This is the first report about transcriptome profile of a mouse model for congenital MD and Dmd(mdx)/Large(myd). By comparing the studied profiles, we conclude that alterations in biological functions due to the dystrophic process are very similar, and that the intense regeneration in Dmd(mdx) involves a large number of activated genes, not differentially expressed in the other two strains.
Collapse
Affiliation(s)
- Camila F Almeida
- Laboratory of Muscle Proteins and Comparative Histopathology, Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Poliana Cm Martins
- Laboratory of Muscle Proteins and Comparative Histopathology, Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Mariz Vainzof
- Laboratory of Muscle Proteins and Comparative Histopathology, Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
4
|
Expression of the myosin heavy chain IIB gene in porcine skeletal muscle: the role of the CArG-Box promoter response element. PLoS One 2014; 9:e114365. [PMID: 25469802 PMCID: PMC4255089 DOI: 10.1371/journal.pone.0114365] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 11/07/2014] [Indexed: 01/09/2023] Open
Abstract
Due to its similarity to humans, the pig is increasingly being considered as a good animal model for studying a range of human diseases. Despite their physiological similarities, differential expression of the myosin heavy chain (MyHC) IIB gene (MYH4) exists in the skeletal muscles of these species, which is associated with a different muscle phenotype. The expression of different MyHC isoforms is a critical determinant of the contractile and metabolic characteristics of the muscle fibre. We aimed to elucidate whether a genomic mechanism was responsible for the drastically different expression of MYH4 between pigs and humans, thus improving our understanding of the pig as a model for human skeletal muscle research. We utilized approximately 1 kb of the MYH4 promoter from a domestic pig and a human (which do and do not express MYH4, respectively) to elucidate the role of the promoter sequence in regulating the high expression of MYH4 in porcine skeletal muscle. We identified a 3 bp genomic difference within the proximal CArG and E-box region of the MYH4 promoter of pigs and humans that dictates the differential activity of these promoters during myogenesis. Subtle species-specific genomic differences within the CArG-box region caused differential protein-DNA interactions at this site and is likely accountable for the differential MYH4 promoter activity between pigs and humans. We propose that the genomic differences identified herein explain the differential activity of the MYH4 promoter of pigs and humans, which may contribute to the differential expression patterns displayed in these otherwise physiologically similar mammals. Further, we report that both the pig and human MYH4 promoters can be induced by MyoD over-expression, but the capacity to activate the MYH4 promoter is largely influenced by the 3 bp difference located within the CArG-box region of the proximal MYH4 promoter.
Collapse
|
5
|
Patel AK, Shah RK, Patel UA, Tripathi AK, Joshi CG. Goat activin receptor type IIB knockdown by muscle specific promoter driven artificial microRNAs. J Biotechnol 2014; 187:87-97. [PMID: 25107506 DOI: 10.1016/j.jbiotec.2014.07.450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 07/20/2014] [Accepted: 07/25/2014] [Indexed: 01/30/2023]
Abstract
Activin receptor type IIB (ACVR2B) is a transmembrane receptor which mediates signaling of TGF beta superfamily ligands known to function in regulation of muscle mass, embryonic development and reproduction. ACVR2B antagonism has shown to enhance the muscle growth in several disease and transgenic models. Here, we show ACVR2B knockdown by RNA interference using muscle creatine kinase (MCK) promoter driven artificial microRNAs (amiRNAs). Among the various promoter elements tested, the ∼1.26 kb MCK promoter region showed maximum transcriptional activity in goat myoblasts cells. We observed up to 20% silencing in non-myogenic 293T cells and up to 32% silencing in myogenic goat myoblasts by MCK directed amiRNAs by transient transfection. Goat myoblasts stably integrated with MCK directed amiRNAs showed merely 8% silencing in proliferating myoblasts which was increased to 34% upon induction of differentiation at transcript level whereas up to 57% silencing at protein level. Knockdown of ACVR2B by 5'-UTR derived amiRNAs resulted in decreased SMAD2/3 signaling, increased expression of myogenic regulatory factors (MRFs) and enhanced proliferation and differentiation of myoblasts. Unexpectedly, knockdown of ACVR2B by 3'-UTR derived amiRNAs resulted in increased SMAD2/3 signaling, reduced expression of MRFs and suppression of myogenesis. Our study offers muscle specific knockdown of ACVR2B as a potential strategy to enhance muscle mass in the farm animal species.
Collapse
Affiliation(s)
- Amrutlal K Patel
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand 388001, India
| | - Ravi K Shah
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand 388001, India
| | - Utsav A Patel
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand 388001, India
| | - Ajai K Tripathi
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Chaitanya G Joshi
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand 388001, India.
| |
Collapse
|
6
|
Schwartz B, Marks M, Wittler L, Werber M, Währisch S, Nordheim A, Herrmann BG, Grote P. SRF is essential for mesodermal cell migration during elongation of the embryonic body axis. Mech Dev 2014; 133:23-35. [PMID: 25020278 DOI: 10.1016/j.mod.2014.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 07/01/2014] [Accepted: 07/03/2014] [Indexed: 12/22/2022]
Abstract
Mesoderm formation in the mouse embryo initiates around E6.5 at the primitive streak and continues until the end of axis extension at E12.5. It requires the process of epithelial-to-mesenchymal transition (EMT), wherein cells detach from the epithelium, adopt mesenchymal cell morphology, and gain competence to migrate. It was shown previously that, prior to mesoderm formation, the transcription factor SRF (Serum Response Factor) is essential for the formation of the primitive streak. To elucidate the role of murine Srf in mesoderm formation during axis extension we conditionally inactivated Srf in nascent mesoderm using the T(s)::Cre driver mouse. Defects in mutant embryos became apparent at E8.75 in the heart and in the allantois. From E9.0 onwards body axis elongation was arrested. Using genome-wide expression analysis, combined with SRF occupancy data from ChIP-seq analysis, we identified a set of direct SRF target genes acting in posterior nascent mesoderm which are enriched for transcripts associated with migratory function. We further show that cell migration is impaired in Srf mutant embryos. Thus, the primary role for SRF in the nascent mesoderm during elongation of the embryonic body axis is the activation of a migratory program, which is a prerequisite for axis extension.
Collapse
Affiliation(s)
- Benedikt Schwartz
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany; Free University Berlin, Dept. of Biology, Chemistry and Pharmacy, Takustrasse 3, 14195 Berlin, Germany
| | - Matthias Marks
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Lars Wittler
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Martin Werber
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Sandra Währisch
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Alfred Nordheim
- Department of Molecular Biology, Interfaculty Institute for Cell Biology, University of Tübingen, 72076 Tübingen, Germany
| | - Bernhard G Herrmann
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Phillip Grote
- Max Planck Institute for Molecular Genetics, Department of Developmental Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany.
| |
Collapse
|
7
|
Hu X, Guo H, He Y, Wang S, Zhang L, Wang S, Huang X, Roy SW, Lu W, Hu J, Bao Z. Molecular characterization of Myostatin gene from Zhikong scallop Chlamys farreri (Jones et Preston 1904). Genes Genet Syst 2011; 85:207-18. [PMID: 21041979 DOI: 10.1266/ggs.85.207] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The scallop is an economically important sea food prized for its large and delicious adductor muscle. Studying the molecular basis of scallop muscle growth is important for both scallop breeding and our understanding of muscle mass regulation in bivalve. Myostatin (MSTN) is a conserved negative regulator of muscle growth and development. Here we report the MSTN gene from Zhikong scallop (Chlamys farreri Jones et Preston 1904). The C. farreri MSTN consists of 11651 nucleotides encoding 457 amino acids. The gene has a 3-exon/2-intron structure that is conserved with vertebrate homologs. The exons are 586, 380 and 408 bp in length, respectively, and separated by introns of 5086 and 1518 bp. The protein sequence contains characteristic conserved residues including a cleavage motif of proteolysis (RXXR) and nine cysteines. Three transcription initiation sites were found at 62, 146, and 296 bp upstream of the translation start codon ATG. In silico analysis of the promoter region identified a TATA-box and several muscle-specific regulatory elements including COMP, MEF2s, MTBFs and E-boxes. Minisatellite DNA was found in intron 1. By fluorescence in situ hybridization (FISH), the gene was mapped to the long arm of a pair of middle subtelocentric chromosome. Quantitative analysis of MSTN transcripts in embryos/larvae indicated high expression level in gastrulae and limited expression at other stages. In adult scallops, MSTN is predominantly expressed in striated muscle, with different expression levels in other tissues. Our data provide valuable genomic and expression information which will aid the further study on scallop MSTN function and MSTN evolution.
Collapse
Affiliation(s)
- Xiaoli Hu
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Li D, Niu Z, Yu W, Qian Y, Wang Q, Li Q, Yi Z, Luo J, Wu X, Wang Y, Schwartz RJ, Liu M. SMYD1, the myogenic activator, is a direct target of serum response factor and myogenin. Nucleic Acids Res 2010; 37:7059-71. [PMID: 19783823 PMCID: PMC2790895 DOI: 10.1093/nar/gkp773] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
SMYD1 is a heart and muscle specific SET-MYND domain containing protein, which functions as a histone methyltransferase and regulates downstream gene transcription. We demonstrated that the expression of SMYD1 is restricted in the heart and skeletal muscle tissues in human. To reveal the regulatory mechanisms of SMYD1 expression during myogenesis and cardiogenesis, we cloned and characterized the human SMYD1 promoter, which contains highly conserved serum response factor (SRF) and myogenin binding sites. Overexpression of SRF and myogenin significantly increased the endogenous expression level of Smyd1 in C2C12 cells, respectively. Deletion of Srf in the heart of mouse embryos dramatically decreased the expression level of Smyd1 mRNA and the expression of Smyd1 can be rescued by exogenous SRF introduction in SRF null ES cells during differentiation. Furthermore, we demonstrated that SRF binds to the CArG site and myogenin binds to the E-box element on Smyd1 promoter region using EMSA and ChIP assays. Moreover, forced expression of SMYD1 accelerates myoblast differentiation and myotube formation in C2C12 cells. Taken together, these studies demonstrated that SMYD1 is a key regulator of myogenic differentiation and acts as a downstream target of muscle regulatory factors, SRF and myogenin.
Collapse
Affiliation(s)
- Dali Li
- The Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Du R, Chen YF, An XR, Yang XY, Ma Y, Zhang L, Yuan XL, Chen LM, Qin J. Cloning and sequence analysis of myostatin promoter in sheep. ACTA ACUST UNITED AC 2009; 16:412-7. [PMID: 16287620 DOI: 10.1080/10425170500226474] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
To better understand the structure and function of the myostatin's gene promoter region in sheep, we cloned and sequenced a 1.517 kb fragment containing the 5'-regulatory region of the sheep myostatin gene (GenBank accession number is AY918121). The promoter sequence consists of three TATA boxes, one CAAT box, and eight putative E-boxes. Some putative muscle growth response elements for Octamer-binding factor 1(Octamer), Activator protein 1(AP1), Growth factor independence 1 zinc finger protein (Gfi-1B), Myocyte enhancer factor 2 (MEF2), Muscle-specific Mt binding site (MTBF), Glucocorticoid response elements (GRE) and Progesterone receptor binding site (PRE) were detected. Some of the motifs are conserved as compared to with that in the goat, bovine and porcine myostatin promoters. However, some differences were also found.
Collapse
Affiliation(s)
- Rong Du
- Shanxi Agricultural University, College of Animal Science and Technology, Taigu, Shanxi 030801, PR China.
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
The transcriptional regulation of cardiovascular development requires precise spatiotemporal control of gene expression, and heterozygous mutations of transcription factors have frequently been implicated in human cardiovascular malformations. A novel mechanism involving posttranscriptional regulation by small, noncoding microRNAs (miRNAs) has emerged as a central regulator of many cardiogenic processes. We are beginning to understand the functions that miRNAs play during essential biological processes, such as cell proliferation, differentiation, apoptosis, stress response, and tumorigenesis. The identification of miRNAs expressed in specific cardiac and vascular cell types has led to the discovery of important regulatory roles for these small RNAs during cardiomyocyte differentiation, cell cycle, conduction, vessel formation, and during stages of cardiac hypertrophy in the adult. Here, we overview the recent findings on miRNA regulation in cardiovascular development and report the latest advances in understanding their function by unveiling their mRNA targets. Further analysis of miRNA function during cardiovascular development will allow us to determine the potential for novel miRNA-based therapeutic strategies.
Collapse
Affiliation(s)
- Kimberly R Cordes
- Gladstone Institute of Cardiovascular Disease, 1650 Owens St, San Francisco, CA 94158, USA
| | | |
Collapse
|
11
|
Downregulation of SRF-FOS-JUNB pathway in fumarate hydratase deficiency and in uterine leiomyomas. Oncogene 2009; 28:1261-73. [PMID: 19151755 DOI: 10.1038/onc.2008.472] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Defects of metabolic enzymes result in a variety of manifestations not logically explained by the primary metabolic function. Dominant defects of fumarate hydratase (FH) result in predisposition to cutaneous and uterine leiomyomas, and renal cell cancer. FH is a metabolic enzyme of the tricarboxylic acid cycle, and its tumor-suppressor mechanism is not fully understood. We compared the consequences of FH deficiency and respiratory chain (RC) deficiency using global expression pattern of diploid primary fibroblasts. This approach utilized the information that RC defects do not seem to predispose to tumorigenesis, and the aim was to identify FH-specific signaling effects that might have relevance to tumor formation. These results were then compared to global expression patterns of FH-deficient and sporadic uterine leiomyoma data sets. We show here that FH-deficient fibroblasts share a common transcriptional fingerprint with FH-deficient and sporadic leiomyomas, highlighting the downregulation of serum response factor (SRF)-regulated transcripts, particularly the FOS-JUNB pathway. We confirmed the downregulation of this pathway at transcriptional and protein level. SRF has a fundamental function in the differentiation of smooth muscle progenitor cells, and its downregulation both in diploid FH-deficient primary fibroblasts and in leiomyomas suggests an early function in the mechanism of uterine leiomyoma formation in FH deficiency. Concordantly, the phosphorylated form of SRF, known to activate transcription, is undetectable in leiomyomas whereas clearly detected in several nuclei in the differentiated myometrium. A similar transcriptional SRF-pathway fingerprint in FH-deficient and sporadic leiomyomas emphasizes the potential importance of this pathway in primary events leading to leiomyomatosis.
Collapse
|
12
|
McWhinney C, Robishaw JD. Myocyte-specific M-CAT and MEF-1 elements regulate G-protein gamma 3 gene (gamma3) expression in cardiac myocytes. DNA Cell Biol 2008; 27:367-76. [PMID: 18613791 DOI: 10.1089/dna.2008.0754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Little is known regarding the mechanisms that control the expression of G-protein alpha, beta, and gamma subtypes. We have previously shown that the G-protein gamma(3) gene is expressed in the heart, brain, lung, spleen, kidney, muscle, and testis in mice. We have also reported that the G-protein gamma(3) subunit is expressed in rat cardiac myocytes, but not in cardiac fibroblasts. Other studies have shown that the gamma(3) subunit couples to the angiotensin A1A receptor in portal vein myocytes, and has been shown to mediate beta-adrenergic desensitization in cardiac myocytes treated with atorvastatin. In the present study, we evaluated G-protein gamma(3) promoter-luciferase reporter constructs in primary myocytes to identify key regulatory promoter regions. We identified two important regions of the promoter (upstream promoter region [UPR] and downstream promoter region [DPR]), which are required for expression in cardiac myocytes. We observed that removal of 48 bp in the UPR diminished gene transcription by 75%, and that the UPR contains consensus elements for myocyte-specific M-CAT and myocyte enhancer factor 1 (MEF-1) elements. The UPR and DPR share transcription factor elements for myocyte-specific M-CAT element. We observed that cardiac myocyte proteins bind to gamma(3) oligonucleotides containing transcription factor elements for myocyte-specific M-CAT and MEF-1. Myocyte-specific M-CAT proteins were supershifted with transcriptional enhancer factor-1 (TEF-1) antibodies binding to the gamma(3) M-CAT element, which is in agreement with reports showing that the M-CAT element binds the TEF-1 family of transcription factors. The 150 bp DPR contains three M-CAT elements, an INR element, an upstream stimulatory factor 1 element, and the transcription start site. We have shown that myocyte gamma(3) gene expression is regulated by myocyte-specific M-CAT and MEF-1 elements.
Collapse
Affiliation(s)
- Charlene McWhinney
- Biomedical Sciences Department, New York College of Osteopathic Medicine, Old Westbury, New York 11568-8000, USA.
| | | |
Collapse
|
13
|
Ounzain S, Dacwag CS, Samani NJ, Imbalzano AN, Chong NW. Comparative in silico analysis identifies bona fide MyoD binding sites within the Myocyte stress 1 gene promoter. BMC Mol Biol 2008; 9:50. [PMID: 18489770 PMCID: PMC2408591 DOI: 10.1186/1471-2199-9-50] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 05/19/2008] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Myocyte stress 1 (MS1) is a striated muscle actin binding protein required for the muscle specific activity of the evolutionary ancient myocardin related transcription factor (MRTF)/serum response factor (SRF) transcriptional pathway. To date, little is known about the molecular mechanisms that govern skeletal muscle specific expression of MS1. Such mechanisms are likely to play a major role in modulating SRF activity and therefore muscle determination, differentiation and regeneration. In this study we employed a comparative in silico analysis coupled with an experimental promoter characterisation to delineate these mechanisms. RESULTS Analysis of MS1 expression in differentiating C2C12 muscle cells demonstrated a temporal differentiation dependent up-regulation in ms1 mRNA. An in silico comparative sequence analysis identified two conserved putative myogenic regulatory domains within the proximal 1.5 kbp of 5' upstream sequence. Co-transfecting C2C12 myoblasts with ms1 promoter/luciferase reporters and myogenic regulatory factor (MRF) over-expression plasmids revealed specific sensitivity of the ms1 promoter to MyoD. Subsequent mutagenesis and EMSA analysis demonstrated specific targeting of MyoD at two distinct E-Boxes (E1 and E2) within identified evolutionary conserved regions (ECRs, alpha and beta). Chromatin immunoprecipitation (ChIP) analysis indicates that co-ordinated binding of MyoD at E-Boxes located within ECRs alpha and beta correlates with the temporal induction in ms1 mRNA. CONCLUSION These findings suggest that the tissue specific and differentiation dependent up-regulation in ms1 mRNA is mediated by temporal binding of MyoD at distinct evolutionary conserved E-Boxes within the ms1 5' upstream sequence. We believe, through its activation of ms1, this is the first study to demonstrate a direct link between MyoD activity and SRF transcriptional signalling, with clear implications for the understanding of muscle determination, differentiation and regeneration.
Collapse
Affiliation(s)
- Samir Ounzain
- Cardiology Group, Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester, LE3 9QP, UK.
| | | | | | | | | |
Collapse
|
14
|
Age-related reductions in expression of serum response factor and myocardin-related transcription factor A in mouse skeletal muscles. Biochim Biophys Acta Mol Basis Dis 2008; 1782:453-61. [PMID: 18442487 DOI: 10.1016/j.bbadis.2008.03.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 03/27/2008] [Accepted: 03/28/2008] [Indexed: 11/29/2022]
Abstract
The molecular signaling pathways linking the atrophy of skeletal muscle during aging have not been identified. Using reverse transcription (RT)-PCR, Western blotting, and immunofluorescence microscopy, we investigated whether the amounts of RhoA, RhoGDI, SRF, MRTF-A, and MyoD in the triceps brachii and quadriceps muscles change with aging in mice. Young adult (3 mo) and aged (24 mo) C57BL/6J mice were used. Senescent mice possessed many fibers with central nuclei in the quadriceps muscle. Western blotting using a homogenate of whole muscle or the cytosolic fraction clearly showed that the amount of SRF protein was significantly decreased in the aged skeletal muscles. Immunofluorescence labeling indicated more SRF-positive muscle fibers in young mice. Both young and old mice possessed SRF immunoreactivity in some satellite cells expressing Pax7. MRTF-A and STARS mRNA levels significantly declined with aging in the triceps brachii and quadriceps muscles. The amount of MRTF-A protein was markedly reduced in the nuclear fraction of aged muscle of mice. The amounts of RhoA and RhoGDI in the crude homogenate or the cytosolic and membrane fractions were greater in the aged muscle. Senescent mice possessed significantly higher levels of MyoD protein in the cytosol and nucleus. Decreased SRF and MRTF expression may induce the atrophy of skeletal muscle with aging.
Collapse
|
15
|
The myocardin-related transcription factor, MASTR, cooperates with MyoD to activate skeletal muscle gene expression. Proc Natl Acad Sci U S A 2008; 105:1545-50. [PMID: 18230740 DOI: 10.1073/pnas.0703918105] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The myocardin family proteins (myocardin, MRTF-A, and MRTF-B) are serum response factor (SRF) cofactors and potent transcription activators. Gene-ablation studies have indicated important developmental functions for myocardin family proteins primarily in regulation of cardiac and smooth muscle development. Using Xenopus genome and cDNA databases, we identified a myocardin-related transcription factor expressed specifically in the skeletal muscle lineage. Synteny and sequence alignments indicate that this gene is the frog orthologue of mouse MASTR [Creemers EE, Sutherland LB, Oh J, Barbosa AC, Olson EN (2006) Coactivation of MEF2 by the SAP domain proteins myocardin and MASTR. Mol Cell 23:83-96]. Inhibition of MASTR function in the Xenopus embryo by using dominant-negative constructions or morpholino knockdown results in a dramatic reduction in expression of skeletal muscle marker genes. Overexpression of MASTR in whole embryos or embryonic tissue explants induces ectopic expression of muscle marker genes. Furthermore, MASTR cooperates with the myogenic regulatory factors MyoD and Myf5 to activate transcription of skeletal muscle genes. An essential function for MASTR in regulation of myogenic development in the vertebrate embryo has not been previously indicated.
Collapse
|
16
|
Angelelli C, Magli A, Ferrari D, Ganassi M, Matafora V, Parise F, Razzini G, Bachi A, Ferrari S, Molinari S. Differentiation-dependent lysine 4 acetylation enhances MEF2C binding to DNA in skeletal muscle cells. Nucleic Acids Res 2007; 36:915-28. [PMID: 18086704 PMCID: PMC2241889 DOI: 10.1093/nar/gkm1114] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Myocyte enhancer factor 2 (MEF2) proteins play a key role in promoting the expression of muscle-specific genes in differentiated muscle cells. MEF2 activity is regulated by the association with several transcriptional co-factors and by post-translational modifications. In the present report, we provide evidence for a novel regulatory mechanism of MEF2C activity, which occurs at the onset of skeletal muscle differentiation and is based on Lys4 acetylation. This covalent modification results in the enhancement of MEF2C binding to DNA and chromatin. In particular, we report that the kinetic parameters of MEF2/DNA association change substantially upon induction of differentiation to give a more stable complex and that this effect is mediated by Lys4 acetylation. We also show that Lys4 acetylation plays a prominent role in the p300-dependent activation of MEF2C.
Collapse
Affiliation(s)
- Cecilia Angelelli
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Zammit PS, Cohen A, Buckingham ME, Kelly RG. Integration of embryonic and fetal skeletal myogenic programs at the myosin light chain 1f/3f locus. Dev Biol 2007; 313:420-33. [PMID: 18062958 DOI: 10.1016/j.ydbio.2007.10.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 10/16/2007] [Accepted: 10/26/2007] [Indexed: 12/25/2022]
Abstract
The genetic control of skeletal muscle differentiation at the onset of myogenesis in the embryo is relatively well understood compared to the formation of muscle during the fetal period giving rise to the bulk of skeletal muscle fibers at birth. The Mlc1f/3f (Myl1) locus encodes two alkali myosin light chains, Mlc1f and Mlc3f, from two promoters that are differentially regulated during development. The Mlc1f promoter is active in embryonic, fetal and adult fast skeletal muscle whereas the Mlc3f promoter is upregulated during fetal development and remains on in adult fast skeletal muscle. Two enhancer elements have been identified at the mammalian Mlc1f/3f locus, a 3' element active at all developmental stages and an intronic enhancer activated during fetal development. Here, using transgenesis, we demonstrate that these enhancers act combinatorially to confer the spatial, temporal and quantitative expression profile of the endogenous Mlc3f promoter. Using double reporter transgenes we demonstrate that each enhancer can activate both Mlc1f and Mlc3f promoters in vivo, revealing enhancer sharing rather than exclusive enhancer-promoter interactions. Finally, we demonstrate that the fetal activated enhancer contains critical E-box myogenic regulatory factor binding sites and that enhancer activation is impaired in vivo in the absence of myogenin but not in the absence of innervation. Together our observations provide insights into the regulation of fetal myogenesis and the mechanisms by which temporally distinct genetic programs are integrated at a single locus.
Collapse
Affiliation(s)
- Peter S Zammit
- Department of Developmental Biology, CNRS URA 2578, Pasteur Institute, 28 Rue du Dr Roux, 75724 Paris Cedex 15, France
| | | | | | | |
Collapse
|
18
|
L'honore A, Rana V, Arsic N, Franckhauser C, Lamb NJ, Fernandez A. Identification of a new hybrid serum response factor and myocyte enhancer factor 2-binding element in MyoD enhancer required for MyoD expression during myogenesis. Mol Biol Cell 2007; 18:1992-2001. [PMID: 17377068 PMCID: PMC1877109 DOI: 10.1091/mbc.e06-09-0867] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 02/06/2007] [Accepted: 03/14/2007] [Indexed: 01/19/2023] Open
Abstract
MyoD is a critical myogenic factor induced rapidly upon activation of quiescent satellite cells, and required for their differentiation during muscle regeneration. One of the two enhancers of MyoD, the distal regulatory region, is essential for MyoD expression in postnatal muscle. This enhancer contains a functional divergent serum response factor (SRF)-binding CArG element required for MyoD expression during myoblast growth and muscle regeneration in vivo. Electrophoretic mobility shift assay, chromatin immunoprecipitation, and microinjection analyses show this element is a hybrid SRF- and MEF2 Binding (SMB) sequence where myocyte enhancer factor 2 (MEF2) complexes can compete out binding of SRF at the onset of differentiation. As cells differentiate into postmitotic myotubes, MyoD expression no longer requires SRF but instead MEF2 binding to this dual-specificity element. As such, the MyoD enhancer SMB element is the site for a molecular relay where MyoD expression is first initiated in activated satellite cells in an SRF-dependent manner and then increased and maintained by MEF2 binding in differentiated myotubes. Therefore, SMB is a DNA element with dual and stage-specific binding activity, which modulates the effects of regulatory proteins critical in controlling the balance between proliferation and differentiation.
Collapse
Affiliation(s)
- Aurore L'honore
- Cell Biology Unit, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 34396 Montpellier Cedex 05, France
| | - Vanessa Rana
- Cell Biology Unit, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 34396 Montpellier Cedex 05, France
| | - Nikola Arsic
- Cell Biology Unit, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 34396 Montpellier Cedex 05, France
| | - Celine Franckhauser
- Cell Biology Unit, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 34396 Montpellier Cedex 05, France
| | - Ned J. Lamb
- Cell Biology Unit, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 34396 Montpellier Cedex 05, France
| | - Anne Fernandez
- Cell Biology Unit, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 34396 Montpellier Cedex 05, France
| |
Collapse
|
19
|
Chen YM, Wei CY, Chien CH, Chang HW, Huang SI, Yang HL, Chen TY. Myostatin gene organization and nodavirus-influenced expression in orange-spotted grouper (Epinephelus coioides). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2007; 2:215-27. [PMID: 20483295 DOI: 10.1016/j.cbd.2007.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 04/21/2007] [Accepted: 04/23/2007] [Indexed: 11/24/2022]
Abstract
The relationship(s) between nodavirus infection and myostatin expression in the skeletal muscle tissue of grouper is unclear. To investigate, the grouper (Epinephelus coioides) myostatin gene was cloned and cDNA was utilized to examine the expression of the gene in skeletal muscle and serum of healthy (uninfected) grouper and fish naturally infected with nodavirus. The myostatin gene comprises three exons and two introns and is transcribed as a 2778-bp mRNA length that encodes a 376-aa precursor protein. All exon-intron boundaries conformed to the consensus sequences. Alignment of the upstream sequences indicated that the grouper myostatin promoter has been highly conserved during evolution. Sequence analyses of 1936 bp of the upstream region revealed ten E-box motifs. The protein was consistent with the predicted molecular weight (approximately 42 kDa) of the unprocessed monomeric precursor protein and the processed myostatin form of the protein secreted into the plasma. Transient transfection studies revealed that the activity of the myostatin promoter decreased in a subset of viral titers. Grouper naturally infected with nodavirus displayed downregulation of the myostatin protein.
Collapse
Affiliation(s)
- Y-M Chen
- Laboratory of Molecular Genetics, Institute of Biotechnology, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
| | | | | | | | | | | | | |
Collapse
|
20
|
Tshori S, Sonnenblick A, Yannay-Cohen N, Kay G, Nechushtan H, Razin E. Microphthalmia transcription factor isoforms in mast cells and the heart. Mol Cell Biol 2007; 27:3911-9. [PMID: 17438132 PMCID: PMC1900032 DOI: 10.1128/mcb.01455-06] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The microphthalmia transcription factor (Mitf) is critical for the survival and differentiation of a variety of cell types. While on the transcript level it has been noted that melanocytes and cardiomyocytes express specific Mitf isoforms, mast cells express several isoforms, mainly Mitf-H and Mitf-MC, whose function has not been thoroughly investigated. We found that in mast cells the expression of the specific Mitf isoforms is dependent on physiological stimuli that cause a major shifting of promoter usage and internal splicing. For example, activation of the c-kit signaling pathway almost totally abolished one of the main splice isoforms. Since cardiomyocytes express only the Mitf-H isoform, they were an ideal system to determine this isoform's physiological role. We identified that the expression of myosin light-chain 1a (MLC-1a) is regulated by Mitf-H. Interestingly, the transactivation of MLC-1a by Mitf-H in cardiomyocytes is decreased by overexpression of the splice form with exon 6a. In conclusion, we found that there is physiological switching of Mitf isoforms and that the promoter context and the cell context have a combined influence on gene expression programs.
Collapse
Affiliation(s)
- Sagi Tshori
- Department of Biochemistry, Hebrew University Medical School, Jerusalem 91120, Israel
| | | | | | | | | | | |
Collapse
|
21
|
Characterization and functional analysis of the 5' flanking region of myosin light chain-2 gene expressed in white muscle of the gilthead sea bream (Sparus aurata). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2007; 2:187-99. [PMID: 20483292 DOI: 10.1016/j.cbd.2007.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 04/01/2007] [Accepted: 04/02/2007] [Indexed: 11/22/2022]
Abstract
The promoter region ( approximately 1400 bp) of myosin light chain 2 gene of fast skeletal muscle from the marine fish Sparus aurata was cloned, sequenced and characterized. It contains a consensus sequence for TATA box, six perfect E-boxes known as binding sites to myogenic basic helix-loop-helix transcription factors and four putative MEF2-binding sites. Three genomic fragments (truncated at their upstream region) of 244, 650 and 1400 bp showed promoter activity evidenced by muscle-specific reporter gene activity using transient expression of green fluorescent protein in microinjected zebrafish embryos and in skeletal muscle of S. aurata fry following intramuscularly injection of plasmid DNA. The three genomic fragments also directed luciferase activity in skeletal muscle of S. aurata fry following intramuscularly injection of plasmid DNA showing a 60 to 150-fold higher luciferase activity compared to that obtained with pGL3-Basic. These experiments show that the three genomic fragments are functional muscle-specific promoters which will be useful for directing myostatin and follistatin expression in fish muscle in order to study their effect on fish muscle growth.
Collapse
|
22
|
Pasquet S, Naye F, Faucheux C, Bronchain O, Chesneau A, Thiébaud P, Thézé N. Transcription Enhancer Factor-1-dependent Expression of the α-Tropomyosin Gene in the Three Muscle Cell Types. J Biol Chem 2006; 281:34406-20. [PMID: 16959782 DOI: 10.1074/jbc.m602282200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In vertebrates, the actin-binding proteins tropomyosins are encoded by four distinct genes that are expressed in a complex pattern during development and muscle differentiation. In this study, we have characterized the transcriptional machinery of the alpha-tropomyosin (alpha-Tm) gene in muscle cells. Promoter analysis revealed that a 284-bp proximal promoter region of the Xenopus laevis alpha-Tm gene is sufficient for maximal activity in the three muscle cell types. The transcriptional activity of this promoter in the three muscle cell types depends on both distinct and common cis-regulatory sequences. We have identified a 30-bp conserved sequence unique to all vertebrate alpha-Tm genes that contains an MCAT site that is critical for expression of the gene in all muscle cell types. This site can bind transcription enhancer factor-1 (TEF-1) present in muscle cells both in vitro and in vivo. In serum-deprived differentiated smooth muscle cells, TEF-1 was redistributed to the nucleus, and this correlated with increased activity of the alpha-Tm promoter. Overexpression of TEF-1 mRNA in Xenopus embryonic cells led to activation of both the endogenous alpha-Tm gene and the exogenous 284-bp promoter. Finally, we show that, in transgenic embryos and juveniles, an intact MCAT sequence is required for correct temporal and spatial expression of the 284-bp gene promoter. This study represents the first analysis of the transcriptional regulation of the alpha-Tm gene in vivo and highlights a common TEF-1-dependent regulatory mechanism necessary for expression of the gene in the three muscle lineages.
Collapse
|
23
|
Wang CC, Chen JJW, Yang PC. Multifunctional transcription factor YY1: a therapeutic target in human cancer? Expert Opin Ther Targets 2006; 10:253-66. [PMID: 16548774 DOI: 10.1517/14728222.10.2.253] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The multifunctional transcription factor Yin Yang 1 (YY1) is a complex protein that has been shown to play pivotal roles in development, differentiation, cellular proliferation and apoptosis. It can act as a transcriptional repressor, an activator, or an initiator element binding protein that directs and initiates transcription of numerous cellular and viral genes. Because the expression and function of YY1 are known to be intimately associated with cell-cycle progression, the physiological significance of YY1 activity has recently been applied to models of cancer biology. Several lines of evidence imply that YY1 expression and/or activation is associated with tumourigenesis, in addition to its regulatory roles in normal biological processes. However, controversial results also raised and indicated that further studies are still needed to piece all of the seemingly contradictory data into a complete picture. On the basis of YY1 regulations and functions, novel drugs and specific treatment strategies may be developed with new therapeutic applications for tumour patients in the future.
Collapse
Affiliation(s)
- Chi-Chung Wang
- National Taiwan University College of Medicine, NTU Center for Genomic Medicine, Taipei, Taiwan, Republic of China
| | | | | |
Collapse
|
24
|
McLellan AS, Kealey T, Langlands K. An E box in the exon 1 promoter regulates insulin-like growth factor-I expression in differentiating muscle cells. Am J Physiol Cell Physiol 2006; 291:C300-7. [PMID: 16554406 DOI: 10.1152/ajpcell.00345.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin-like growth factor (IGF)-I expression is subject to complex temporal and spatial regulation. Endocrine synthesis occurs in the liver, where transcription is initiated from promoters located in either exon 1 (P1) or in exon 2 (P2), whereas local transcription is mainly initiated from P1. IGF-I is expressed in a range of tissues and, in particular, is an important regulator of skeletal muscle mass, although the mechanisms of tissue-specific regulation remain to be fully characterized. Gene regulation in skeletal muscle is associated with the E box DNA element (5′-CANNTG-3′) recognized by myogenic regulatory factors (MRFs), such as MyoD1. Transcription element profiling identified a hypothetical myogenic E box (sequence 5′-CAGCTG-3′) within P1, immediately upstream of the major muscle transcriptional start site, and we sought to test its activity in differentiating C2C12 myoblasts. We found P1-driven IGF-I mRNA expression to be associated with myogenic differentiation and, moreover, that a single base-pair mutation in the E box specifically reduced expression in myofibers. A synthetic enhancer construct containing a triplet repeat of the E box was active in muscle cells and strongly induced in myofibers. The capacity of a double-stranded IGF-I E box probe (but not one bearing a single-base pair alteration) to bind C2C12 nuclear lysates increased with myogenesis, and a transactivation assay demonstrated that the E box was recognized by E protein-MRF heterodimers. Mechanisms of tissue-specific gene activation are of increasing biological interest, and we have identified a cis-element able to direct muscle-specific IGF-I gene expression.
Collapse
Affiliation(s)
- A S McLellan
- Clore Laboratory, Univ. of Buckingham, Hunter St., Buckingham, MK18 1EG, UK
| | | | | |
Collapse
|
25
|
Mikheev AM, Inoue A, Jing L, Mikheeva SA, Li V, Leanderson T, Zarbl H. Frequent activation of CArG binding factor-A expression and binding in N-methyl-N-nitrosourea-induced rat mammary carcinomas. Breast Cancer Res Treat 2005; 88:95-102. [PMID: 15538050 DOI: 10.1007/s10549-004-1280-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We previously identified a positive transcriptional element identical to human Ha-ras response element (HRE) within the promoter of the rat Ha-ras gene. We further identified CArG binding factor A (CBF-A), a member of heterogeneous nuclear ribonuclear protein (hnRNP) gene family, as a trans-acting factor that binds the HRE sequence with high affinity in rat mammary carcinoma cells. To determine if activation of CBF-A plays a role in tumor development in vivo , we investigated CBF-A expression and binding activity in rat mammary tumors induced by N-methyl-N-nitrosourea. We found that approximately 82% of tumors expressed CBF-A at levels that were 3-20 fold higher than detected in normal mammary gland. Moreover, elevated CBF-A protein levels were invariably associated with increased binding activity to the HRE. CBF-A mRNA levels in tumors were on average elevated only two fold as compared to normal mammary gland, indicating that increased CBF-A protein levels in tumors resulted from both translational and/or post-translational regulation. The level of CBF-A expression in mammary tumors was independent of Ha-ras mutational status. Together, these findings indicated that deregulation of CBF-A contributes to mammary carcinogenesis via a mechanism that is distinct from its hnRNP functions in binding and post-transcriptional regulation of RNA.
Collapse
|
26
|
Wang DZ, Olson EN. Control of smooth muscle development by the myocardin family of transcriptional coactivators. Curr Opin Genet Dev 2005; 14:558-66. [PMID: 15380248 DOI: 10.1016/j.gde.2004.08.003] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Differentiation of smooth muscle cells (SMCs) is accompanied by the transcriptional activation of an array of muscle-specific genes that confer the unique contractile and physiologic properties of this muscle cell type. The majority of smooth muscle genes are controlled by serum response factor (SRF), a widely expressed transcription factor that also regulates genes involved in cell proliferation. Myocardin and myocardin-related transcription factors (MRTFs) interact with SRF and potently stimulate SRF-dependent transcription. Gain- and loss-of-function experiments have shown myocardin to be sufficient and necessary for SMC differentiation. SMCs are highly plastic and can switch between differentiated and proliferative states in response to extracellular cues. Suppression of SMC differentiation by growth factor signaling is mediated, at least in part, by the displacement of myocardin from SRF by growth factor-dependent ternary complex factors. The association of SRF with myocardin and MRTFs provides a molecular basis for the activation of SMC genes by SRF and the responsiveness of the smooth muscle differentiation program to growth factor signaling.
Collapse
Affiliation(s)
- Da-Zhi Wang
- Carolina Cardiovascular Biology Center, Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina 27599-7126, USA
| | | |
Collapse
|
27
|
Zhao W, Wu Y, Zhao J, Guo S, Bauman WA, Cardozo CP. Structure and function of the upstream promotor of the humanMafbx gene: The proximal upstream promotor modulates tissue-specificity. J Cell Biochem 2005; 96:209-19. [PMID: 16052482 DOI: 10.1002/jcb.20468] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Muscle loss has been linked to increased expression of an ubiquitin ligase termed muscle atrophy F-box (MAFbx), a nuclear protein involved in degradation of MyoD. To gain insights into mechanisms by which the human MAFbx gene is controlled, the structure of its upstream promotor were studied, and its expression in cultured cells was characterized. Expression of MAFbx was found only in cells of muscle lineage. A reporter gene controlled by 948 bases of human MAFbx upstream promotor displayed similar cell-type selectivity. MAFbx levels were greatly enhanced upon myogenic differentiation of C2C12 myoblasts, and differentiation markedly increased activity of a reporter gene constructed with 400 bp of upstream promotor from the MAFbx gene. The core promotor spanned approximately 160 bases beginning at -241 bp upstream of the first codon, included potential binding sites for MyoD and myogenin, and was highly conserved among mouse, rat, and humanMAFbx genes. The major transcription start site for the human MAFbx gene was 340 bases upstream of the ATG and was localized the highly conserved region of 140 bp. The findings indicate an important role for the immediate upstream promotor of the human MAFbx gene in mediating its developmental expression and tissue specificity.
Collapse
Affiliation(s)
- Weidong Zhao
- VA Rehabilitation Research and Development Service Center of Excellence, Bronx VA Medical Center, Bronx, New York, USA
| | | | | | | | | | | |
Collapse
|
28
|
Li CY, Zhu J, Wang JYJ. Ectopic Expression of p73α, but Not p73β, Suppresses Myogenic Differentiation. J Biol Chem 2005; 280:2159-64. [PMID: 15545283 DOI: 10.1074/jbc.m411194200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The TRP73 gene, a member of the p53 family, encodes several variants through differential splicing and use of alternative promoters. At the N terminus, two different promoters generate the full-length and the DeltaN isoforms, with or without the transactivating domain. At the C terminus, seven isoforms generated through alternative splicing have been cloned. Previous studies have demonstrated that DeltaN-p73 interferes with p73-induced apoptosis. However, there has been no evidence for functional diversity of the C-terminal p73 variants. In this study, we found that p73alpha and p73beta exerted differential effect on the differentiation of C2C12 myoblasts. Although p73beta lacked any detectable effect on differentiation, p73alpha caused a substantial delay in the expression of muscle-specific genes. In co-transfection experiments p73alpha, but not p73beta, attenuated the transcriptional activity of MyoD. Microarray-based gene profiling confirmed the protraction of MyoD-dependent gene expression in C2C12 cells stably expressing p73alpha. Notwithstanding the differential effect on differentiation, p73alpha and p73beta showed similar activity in sensitizing C2C12 myoblasts to cisplatin-induced cell death. These results demonstrated a functional diversity between the two C-terminal variants of p73 and suggested that p73alpha can regulate cellular differentiation in addition to its role in stimulating cell death.
Collapse
Affiliation(s)
- Chun-Ying Li
- Division of Biological Sciences and Moores Cancer Center, University of California, San Diego, La Jolla, California 92093-0322, USA
| | | | | |
Collapse
|
29
|
Lemonnier M, Buckingham ME. Characterization of a cardiac-specific enhancer, which directs {alpha}-cardiac actin gene transcription in the mouse adult heart. J Biol Chem 2004; 279:55651-8. [PMID: 15491989 DOI: 10.1074/jbc.m411082200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Expression of the mouse alpha-cardiac actin gene in skeletal and cardiac muscle is regulated by enhancers lying 5' to the proximal promoter. Here we report the characterization of a cardiac-specific enhancer located within -2.354/-1.36 kbp of the gene, which is active in cardiocytes but not in C2 skeletal muscle cells. In vivo it directs reporter gene expression to the adult heart, where the proximal promoter alone is inactive. An 85-bp region within the enhancer is highly conserved between human and mouse and contains a central AT-rich site, which is essential for enhancer activity. This site binds myocyte enhancer factor (MEF)2 factors, principally MEF2D and MEF2A in cardiocyte nuclear extracts. These results are discussed in the context of MEF2 activity and of the regulation of the alpha-cardiac actin locus.
Collapse
MESH Headings
- Actins/chemistry
- Animals
- Animals, Genetically Modified
- Base Sequence
- Binding Sites
- Binding, Competitive
- Cell Line
- Cell Nucleus/metabolism
- Cells, Cultured
- DNA/metabolism
- DNA-Binding Proteins/metabolism
- Enhancer Elements, Genetic
- Gene Expression Regulation
- Gene Expression Regulation, Developmental
- Genes, Reporter
- Genome
- Heart/embryology
- Heart/physiology
- Humans
- MADS Domain Proteins
- MEF2 Transcription Factors
- Mice
- Mice, Inbred C3H
- Mice, Transgenic
- Models, Genetic
- Molecular Sequence Data
- Muscle, Skeletal/metabolism
- Mutagenesis, Site-Directed
- Mutation
- Myocardium/metabolism
- Myogenic Regulatory Factors
- Promoter Regions, Genetic
- Rats
- Rats, Wistar
- Time Factors
- Transcription Factors/metabolism
- Transcription, Genetic
- Transfection
- beta-Galactosidase/metabolism
Collapse
Affiliation(s)
- Marguerite Lemonnier
- CNRS URA 2578, Département de Biologie du Développement, Institut Pasteur, 25-28 rue du Dr Roux, 75724 Paris Cedex 15, France
| | | |
Collapse
|
30
|
Wilson-Rawls J, Rhee JM, Rawls A. Paraxis is a basic helix-loop-helix protein that positively regulates transcription through binding to specific E-box elements. J Biol Chem 2004; 279:37685-92. [PMID: 15226298 DOI: 10.1074/jbc.m401319200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Members of the Twist subfamily of basic helix-loop-helix transcription factors are important for the specification of mesodermal derivatives during vertebrate embryogenesis. This subfamily includes both transcriptional activators such as scleraxis, Hand2, and Dermo-1 and repressors such as Twist and Hand1. Paraxis is a member of this subfamily, and it has been shown to regulate morphogenetic events during somitogenesis, including the transition of cells from mesenchyme to epithelium and maintaining anterior/posterior polarity. Mice deficient in paraxis exhibit a caudal truncation of the axial skeleton and fusion of the vertebrae. Considering the developmental importance of paraxis, it is important for future studies to understand the molecular basis of its activity. Here we demonstrate that paraxis can function as a transcriptional activator when it forms a heterodimer with E12. Paraxis is able to bind to a set of E-boxes that overlaps with the closely related scleraxis. Paraxis expression precedes that of scleraxis in the region of the somite fated to form the axial skeleton and tendons and is able to direct transcription from an E-box found in the scleraxis promoter. Further, in the absence of paraxis, Pax-1 is no longer expressed in the somites and presomitic mesoderm. These results suggest that paraxis may regulate early events during chondrogenesis by positively directing transcription of sclerotome-specific genes.
Collapse
|
31
|
Salerno MS, Thomas M, Forbes D, Watson T, Kambadur R, Sharma M. Molecular analysis of fiber type-specific expression of murine myostatin promoter. Am J Physiol Cell Physiol 2004; 287:C1031-40. [PMID: 15189813 DOI: 10.1152/ajpcell.00492.2003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myostatin is a negative regulator of muscle growth, and absence of the functional myostatin protein leads to the heavy muscle phenotype in both mouse and cattle. Although the role of myostatin in controlling muscle mass is established, little is known of the mechanisms regulating the expression of the myostatin gene. In this study, we have characterized the murine myostatin promoter in vivo. Various constructs of the murine myostatin promoter were injected into the quadriceps muscle of mice, and the reporter luciferase activity was analyzed. The results indicate that of the seven E-boxes present in the 2.5-kb fragment of the murine myostatin promoter, the E5 E-box plays an important role in the regulation of promoter activity in vivo. Furthermore, the in vitro studies demonstrated that MyoD preferentially binds and upregulates the murine myostatin promoter activity. We also analyzed the activity of the bovine and murine promoters in murine skeletal muscle and showed that, despite displaying comparable levels of activity in murine myoblast cultures, bovine myostatin promoter activity is much weaker than murine myostatin promoter in mice. Finally, we demonstrate that in vivo, the 2.5-kb region of the murine myostatin promoter is sufficient to drive the activity of the reporter gene in a fiber type-specific manner.
Collapse
Affiliation(s)
- Mônica Senna Salerno
- Animal Genomics, AgResearch, Ruakura Research Centre, Private Bag 3123, East St., Hamilton, New Zealand
| | | | | | | | | | | |
Collapse
|
32
|
Chang THT, Primig M, Hadchouel J, Tajbakhsh S, Rocancourt D, Fernandez A, Kappler R, Scherthan H, Buckingham M. An enhancer directs differential expression of the linked Mrf4 and Myf5 myogenic regulatory genes in the mouse. Dev Biol 2004; 269:595-608. [PMID: 15110722 DOI: 10.1016/j.ydbio.2004.02.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2003] [Revised: 02/03/2004] [Accepted: 02/06/2004] [Indexed: 10/26/2022]
Abstract
The myogenic regulatory factors, Mrf4 and Myf5, play a key role in skeletal muscle formation. An enhancer trap approach, devised to isolate positive-acting elements from a 200-kb YAC covering the mouse Mrf4-Myf5 locus in a C2 myoblast assay, yielded an enhancer, A17, which mapped at -8 kb 5' of Mrf4 and -17 kb 5' of Myf5. An E-box bound by complexes containing the USF transcription factor is critical for enhancer activity. In transgenic mice, A17 gave two distinct and mutually exclusive expression profiles before birth, which correspond to two phases of Mrf4 transcription. Linked to the Tk or Mrf4 minimal promoters, the nlacZ reporter was expressed either in embryonic myotomes, or later in fetal muscle, with the majority of Mrf4 lines showing embryonic expression. When linked to the Myf5 minimal promoter, only fetal muscle expression was detected. These observations identify A17 as a sequence that targets sites of myogenesis in vivo and raise questions about the mutually exclusive modes of expression and possible promoter/enhancer interactions at the Mrf4-Myf5 locus.
Collapse
Affiliation(s)
- Ted Hung-Tse Chang
- Département de Biologie du Développement, CNRS URA 2578, Institut Pasteur, 75724 Paris Cedex 15, France
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Molinari S, Relaix F, Lemonnier M, Kirschbaum B, Schäfer B, Buckingham M. A novel complex regulates cardiac actin gene expression through interaction of Emb, a class VI POU domain protein, MEF2D, and the histone transacetylase p300. Mol Cell Biol 2004; 24:2944-57. [PMID: 15024082 PMCID: PMC371105 DOI: 10.1128/mcb.24.7.2944-2957.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2002] [Revised: 10/23/2002] [Accepted: 01/06/2004] [Indexed: 11/20/2022] Open
Abstract
Expression of the mouse cardiac actin gene depends on a distal enhancer (-7 kbp) which has been shown, in transgenic mice, to direct expression to embryonic skeletal muscle. The presence of this distal sequence is also associated with reproducible expression of cardiac actin transgenes. In differentiated skeletal muscle cells, activity of the enhancer is driven by an E box, binding MyoD family members, and by a 3' AT-rich sequence which is in the location of a DNase I-hypersensitive site. This sequence does not bind MEF2 proteins, or other known muscle transcription factors, directly. Oct1 and Emb, a class VI POU domain protein, bind to consensus sites on the DNA, and it is the binding of Emb which is important for activity. Emb binds as a major complex with MEF2D and the histone transacetylase p300. The form of Emb present in this complex and as a major form in muscle cell extracts is longer (80 kDa) than that previously described. These results demonstrate the importance of this novel complex in the transcriptional regulation of the cardiac actin gene and suggest a potential role in chromatin remodeling associated with muscle gene activation.
Collapse
Affiliation(s)
- S Molinari
- CNRS URA 2578, Department of Developmental Biology, Pasteur Institute, 75724 Paris Cedex 15, France
| | | | | | | | | | | |
Collapse
|
34
|
Laumen H, Brunner C, Greiner A, Wirth T. Myosin light chain 1 atrial isoform (MLC1A) is expressed in pre-B cells under control of the BOB.1/OBF.1 coactivator. Nucleic Acids Res 2004; 32:1577-83. [PMID: 15004244 PMCID: PMC390310 DOI: 10.1093/nar/gkh327] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The BOB.1/OBF.1 protein is a B-cell-specific coactivator of the Oct1 and Oct2 transcription factors. It is involved in mediating the transcriptional activity of the Oct proteins. However, animals deficient for BOB.1/OBF.1 showed virtually normal expression of genes that contain octamer motifs in their regulatory regions. To identify new genes that are regulated by BOB.1/OBF.1, we took advantage of a previously described cell system. RNAs differentially expressed in a BOB.1/OBF.1-deficient pre-B cell line and a derivative of this cell line expressing a hormone dependent BOB.1/OBF.1-estrogen receptor (BobER) fusion protein were isolated. Using the cDNA representational difference analysis method we could identify myosin light chain 1 atrial (MLC1A) isoform as a gene regulated by BOB.1/OBF.1. MLC1A was so far unknown to be expressed in tissues other than muscle. Here we demonstrate that MLC1A is indeed expressed in mouse pre-B cells. Analysis of the expressed mRNA revealed an alternative 5' promoter element and an alternative splice product, which had not yet been described for the murine gene. Cotransfection experiments with reporter constructs driven by the MLC1A promoter suggest that the regulation by BOB.1/OBF.1 is indirect. Consistent with this conclusion is the observation that transcriptional induction of the endogenous MLC1A gene by BOB.1/OBF.1 requires de novo protein synthesis.
Collapse
Affiliation(s)
- Helmut Laumen
- Department of Physiological Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | | | | | | |
Collapse
|
35
|
Mohan RM, Golding S, Heaton DA, Danson EJ, Paterson DJ. Targeting neuronal nitric oxide synthase with gene transfer to modulate cardiac autonomic function. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2004; 84:321-44. [PMID: 14769442 DOI: 10.1016/j.pbiomolbio.2003.11.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microdomains of neuronal nitric oxide synthase (nNOS) are spatially localised within both autonomic neurons innervating the heart and post-junctional myocytes. This review examines the use of gene transfer to investigate the role of nNOS in cardiac autonomic control. Furthermore, it explores techniques that may be used to improve upon gene delivery to the cardiac autonomic nervous system, potentially allowing more specific delivery of genes to the target neurons/myocytes. This may involve modification of the tropism of the adenoviral vector, or the use of alternative viral and non-viral gene delivery mechanisms to minimise potential immune responses in the host. Here we show that adenoviral vectors provide an efficient method of gene delivery to cardiac-neural tissue. Functionally, adenovirus-nNOS can increase cardiac vagal responsiveness by facilitating cholinergic neurotransmission and decrease beta-adrenergic excitability. Whether gene transfer remains the preferred strategy for targeting cardiac autonomic impairment will depend on site-specific promoters eliciting sustained gene expression that results in restoration of physiological function.
Collapse
Affiliation(s)
- R M Mohan
- University Laboratory of Physiology, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | | | | | | | | |
Collapse
|
36
|
L'honore A, Lamb NJ, Vandromme M, Turowski P, Carnac G, Fernandez A. MyoD distal regulatory region contains an SRF binding CArG element required for MyoD expression in skeletal myoblasts and during muscle regeneration. Mol Biol Cell 2003; 14:2151-62. [PMID: 12802082 PMCID: PMC165104 DOI: 10.1091/mbc.e02-07-0451] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We show here that the distal regulatory region (DRR) of the mouse and human MyoD gene contains a conserved SRF binding CArG-like element. In electrophoretic mobility shift assays with myoblast nuclear extracts, this CArG sequence, although slightly divergent, bound two complexes containing, respectively, the transcription factor YY1 and SRF associated with the acetyltransferase CBP and members of C/EBP family. A single nucleotide mutation in the MyoD-CArG element suppressed binding of both SRF and YY1 complexes and abolished DRR enhancer activity in stably transfected myoblasts. This MyoD-CArG sequence is active in modulating endogeneous MyoD gene expression because microinjection of oligonucleotides corresponding to the MyoD-CArG sequence specifically and rapidly suppressed MyoD expression in myoblasts. In vivo, the expression of a transgenic construct comprising a minimal MyoD promoter fused to the DRR and beta-galactosidase was induced with the same kinetics as MyoD during mouse muscle regeneration. In contrast induction of this reporter was no longer seen in regenerating muscle from transgenic mice carrying a mutated DRR-CArG. These results show that an SRF binding CArG element present in MyoD gene DRR is involved in the control of MyoD gene expression in skeletal myoblasts and in mature muscle satellite cell activation during muscle regeneration.
Collapse
Affiliation(s)
- Aurore L'honore
- Cell Biology Unit, Institut de Génétique Humaine, 34396 Montpellier cedex 05, France
| | | | | | | | | | | |
Collapse
|
37
|
Sakuma K, Nishikawa J, Nakao R, Nakano H, Sano M, Yasuhara M. Serum response factor plays an important role in the mechanically overloaded plantaris muscle of rats. Histochem Cell Biol 2003; 119:149-60. [PMID: 12610734 DOI: 10.1007/s00418-003-0499-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2003] [Indexed: 10/25/2022]
Abstract
Molecular signaling pathways linking the hypertrophy after mechanical overloading in vivo have not been identified. Using western blot analysis, immunoprecipitation, and immunohistochemistry, we investigated the effect of the mechanical overloading state on RhoA, serum response factor (SRF), and MyoD in the rat plantaris muscle. Adult male rats (10 weeks of age) were used in this experiment. Compensatory enlargement of the plantaris muscle was induced in one leg of each rat by surgical removal of the ipsilateral soleus and gastrocnemius muscles. In the normal plantaris muscle of rats, slight expression of RhoA and SRF was observed in the quiescent satellite cells possessing CD34 and c-Met. Western blotting using the homogenate of whole muscle clearly showed that mechanical overloading of the plantaris muscle significantly increased the amount of RhoA during 3-6 days postsurgery. Threonine phosphorylation of SRF occurred at 2-4 h after mechanical overloading. The most marked increase in SRF protein was observed in the hypertrophied muscle at 6 days postsurgery. At 2 days postoperation, SRF immunoreactivity was not detected in the proliferating satellite cells possessing bromodeoxyuridine and in the infiltrating macrophages expressing ED1 in the overloaded muscle by surgical removal. The SRF protein was colocalized with RhoA, FAK, and myogenin but not Myf-5 in many mononuclear cells at 6 days of functional overload. At this time, MyoD immunoreactivity was detected in the cytoplasm of mononuclear cells (possibly satellite cell-derived myoblasts) possessing SRF protein at the nucleus. These results suggest that the signaling pathway through RhoA-FAK-SRF is important to the differentiation of satellite cells by interacting MyoD and myogenin in the hypertrophied muscle of rats.
Collapse
Affiliation(s)
- Kunihiro Sakuma
- Department of Legal Medicine, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-hirokoji, Kamigyo-ku, Japan.
| | | | | | | | | | | |
Collapse
|
38
|
Garcia de Veas Lovillo RM, Ruijter JM, Labruyère WT, Hakvoort TBM, Lamers WH. Upstream and intronic regulatory sequences interact in the activation of the glutamine synthetase promoter. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:206-12. [PMID: 12605671 DOI: 10.1046/j.1432-1033.2003.03424.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glutamine synthetase (GS) is expressed at high levels in subsets of cells in some tissues and at low levels in all cells of other tissues, suggesting that the GS gene is surrounded by multiple regulatory elements. We searched for such elements in the 2.5-kb upstream region and in the 2.6-kb first intron of the GS gene, using FTO-2B hepatoma and C2/7 muscle cells as representatives of both cell types and transient transfection assays as our tools. In addition to the entire upstream region and entire intron, an upstream enhancer module at -2.5 kb, and 5', middle and 3' modules of the first intron were tested. The main effects of the respective modules and their combinatorial interactions were quantified using the analysis of variance (anova) technique. The upstream enhancer was strongly stimulatory, the middle intron module strongly inhibitory, and the 3'-intron module weakly stimulatory in both hepatoma and muscle cells. The 5'-intron module was strongly stimulatory in muscle cells only. The major new finding was that in both cell types, the upstream enhancer and 5'-intron module needed to be present simultaneously to fully realize their transactivational potencies. This interaction was responsible for a pronounced inhibitory effect of the 5'-intron module in the absence of the upstream enhancer in hepatoma cells, and for a strong synergistic effect of these two modules, when present simultaneously in muscle cells. The main difference between hepatoma and muscle cells therefore appeared to reside in tissue-specific differences in activity of the respective regulatory elements due to interactions rather than in the existence of tissue-specific regulatory elements.
Collapse
|
39
|
Firulli AB, Thattaliyath BD. Transcription factors in cardiogenesis: the combinations that unlock the mysteries of the heart. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 214:1-62. [PMID: 11893163 DOI: 10.1016/s0074-7696(02)14002-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Heart formation is one of the first signs of organogenesis within the developing embryo and this process is conserved from flies to man. Completing the genetic roadmap of the molecular mechanisms that control the cell specification and differentiation of cells that form the developing heart has been an exciting and fast-moving area of research in the fields of molecular and developmental biology. At the core of these studies is an interest in the transcription factors that are responsible for initiation of a pluripotent cell to become programmed to the cardiac lineage and the subsequent transcription factors that implement the instructions set up by the cells commitment decision. To gain a better understanding of these pathways, cardiac-expressed transcription factors have been identified, cloned, overexpressed, and mutated to try to determine function. Although results vary depending on the gene in question, it is clear that there is a striking evolutionary conservation of the cardiogenic program among species. As we move up the evolutionary ladder toward man, we encounter cases of functional redundancy and combinatorial interactions that reflect the complex networks of gene expression that orchestrate heart development. This review focuses on what is known about the transcription factors implicated in heart formation and the role they play in this intricate genetic program.
Collapse
Affiliation(s)
- Anthony B Firulli
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio 78229, USA
| | | |
Collapse
|
40
|
Spiller MP, Kambadur R, Jeanplong F, Thomas M, Martyn JK, Bass JJ, Sharma M. The myostatin gene is a downstream target gene of basic helix-loop-helix transcription factor MyoD. Mol Cell Biol 2002; 22:7066-82. [PMID: 12242286 PMCID: PMC139803 DOI: 10.1128/mcb.22.20.7066-7082.2002] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myostatin is a negative regulator of myogenesis, and inactivation of myostatin leads to heavy muscle growth. Here we have cloned and characterized the bovine myostatin gene promoter. Alignment of the upstream sequences shows that the myostatin promoter is highly conserved during evolution. Sequence analysis of 1.6 kb of the bovine myostatin gene upstream region revealed that it contains 10 E-box motifs (E1 to E10), arranged in three clusters, and a single MEF2 site. Deletion and mutation analysis of the myostatin gene promoter showed that out of three important E boxes (E3, E4, and E6) of the proximal cluster, E6 plays a significant role in the regulation of a reporter gene in C(2)C(12) cells. We also demonstrate by band shift and chromatin immunoprecipitation assay that the E6 E-box motif binds to MyoD in vitro and in vivo. Furthermore, cotransfection experiments indicate that among the myogenic regulatory factors, MyoD preferentially up-regulates myostatin promoter activity. Since MyoD expression varies during the myoblast cell cycle, we analyzed the myostatin promoter activity in synchronized myoblasts and quiescent "reserve" cells. Our results suggest that myostatin promoter activity is relatively higher during the G(1) phase of the cell cycle, when MyoD expression levels are maximal. However, in the reserve cells, which lack MyoD expression, a significant reduction in the myostatin promoter activity is observed. Taken together, these results suggest that the myostatin gene is a downstream target gene of MyoD. Since the myostatin gene is implicated in controlling G(1)-to-S progression of myoblasts, MyoD could be triggering myoblast withdrawal from the cell cycle by regulating myostatin gene expression.
Collapse
|
41
|
Charrasse S, Meriane M, Comunale F, Blangy A, Gauthier-Rouvière C. N-cadherin-dependent cell-cell contact regulates Rho GTPases and beta-catenin localization in mouse C2C12 myoblasts. J Cell Biol 2002; 158:953-65. [PMID: 12213839 PMCID: PMC2173149 DOI: 10.1083/jcb.200202034] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
N-cadherin, a member of the Ca(2+)-dependent cell-cell adhesion molecule family, plays an essential role in skeletal muscle cell differentiation. We show that inhibition of N-cadherin-dependent adhesion impairs the upregulation of the two cyclin-dependent kinase inhibitors p21 and p27, the expression of the muscle-specific genes myogenin and troponin T, and C2C12 myoblast fusion. To determine the nature of N-cadherin-mediated signals involved in myogenesis, we investigated whether N-cadherin-dependent adhesion regulates the activity of Rac1, Cdc42Hs, and RhoA. N-cadherin-dependent adhesion decreases Rac1 and Cdc42Hs activity, and as a consequence, c-jun NH2-terminal kinase (JNK) MAPK activity but not that of the p38 MAPK pathway. On the other hand, N-cadherin-mediated adhesion increases RhoA activity and activates three skeletal muscle-specific promoters. Furthermore, RhoA activity is required for beta-catenin accumulation at cell-cell contact sites. We propose that cell-cell contacts formed via N-cadherin trigger signaling events that promote the commitment to myogenesis through the positive regulation of RhoA and negative regulation of Rac1, Cdc42Hs, and JNK activities.
Collapse
Affiliation(s)
- Sophie Charrasse
- Centre de Recherche de Biochimie Macromoléculaire, 34293 Montpellier Cedex, France
| | | | | | | | | |
Collapse
|
42
|
Schratt G, Philippar U, Berger J, Schwarz H, Heidenreich O, Nordheim A. Serum response factor is crucial for actin cytoskeletal organization and focal adhesion assembly in embryonic stem cells. J Cell Biol 2002; 156:737-50. [PMID: 11839767 PMCID: PMC2174087 DOI: 10.1083/jcb.200106008] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The activity of serum response factor (SRF), an essential transcription factor in mouse gastrulation, is regulated by changes in actin dynamics. Using Srf(-/-) embryonic stem (ES) cells, we demonstrate that SRF deficiency causes impairments in ES cell spreading, adhesion, and migration. These defects correlate with defective formation of cytoskeletal structures, namely actin stress fibers and focal adhesion (FA) plaques. The FA proteins FA kinase (FAK), beta1-integrin, talin, zyxin, and vinculin were downregulated and/or mislocalized in ES cells lacking SRF, leading to inefficient activation of the FA signaling kinase FAK. Reduced overall actin expression levels in Srf(-/-) ES cells were accompanied by an offset treadmilling equilibrium, resulting in lowered F-actin levels. Expression of active RhoA-V14 rescued F-actin synthesis but not stress fiber formation. Introduction of constitutively active SRF-VP16 into Srf(-/-) ES cells, on the other hand, strongly induced expression of FA components and F-actin synthesis, leading to a dramatic reorganization of actin filaments into stress fibers and lamellipodia. Thus, using ES cell genetics, we demonstrate for the first time the importance of SRF for the formation of actin-directed cytoskeletal structures that determine cell spreading, adhesion, and migration. Our findings suggest an involvement of SRF in cell migratory processes in multicellular organisms.
Collapse
Affiliation(s)
- Gerhard Schratt
- Interfakultäres Institut für Zellbiologie, Abteilung Molekularbiologie, Universität Tübingen, 72076 Tübingen, Germany
| | | | | | | | | | | |
Collapse
|
43
|
Kim SW, Kim HJ, Jung DJ, Lee SK, Kim YS, Kim JH, Kim TS, Lee JW. Retinoid-dependent antagonism of serum response factor transactivation mediated by transcriptional coactivator proteins. Oncogene 2001; 20:6638-42. [PMID: 11641790 DOI: 10.1038/sj.onc.1204695] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2000] [Revised: 05/25/2001] [Accepted: 05/31/2001] [Indexed: 11/09/2022]
Abstract
Transcriptional coactivators SRC-1 and p300 specifically interact with liganded-nuclear receptors and also modulate other transcription factors, including serum response factor (SRF). Here, we report that retinoids repress transactivation by SRF and specific interactions exist between the DNA binding domains of SRF and retinoic acid and retinoid X receptors. We further demonstrate that the repression may involve retinoid-dependent competition for a limiting amount of SRC-1 and p300 between SRF and retinoid receptors. We propose that the well-defined anti-proliferative action of retinoids could, at least in part, result from this novel transrepressive action on the mitogenic transcription factor SRF.
Collapse
Affiliation(s)
- S W Kim
- Center for Ligand and Transcription, Pohang University of Science and Technology, Pohang 790-784, Korea
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Dinev D, Jordan BW, Neufeld B, Lee JD, Lindemann D, Rapp UR, Ludwig S. Extracellular signal regulated kinase 5 (ERK5) is required for the differentiation of muscle cells. EMBO Rep 2001; 2:829-34. [PMID: 11520859 PMCID: PMC1084032 DOI: 10.1093/embo-reports/kve177] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Extracellular signal regulated kinase 5 (ERK5) is a novel member of the mitogen-activated protein kinase (MAPK) family with a poorly defined physiological function. Since ERK5 and its upstream activator MEK5 are abundant in skeletal muscle we examined a function of the cascade during muscle differentiation. We show that ERK5 is activated upon induction of differentiation in mouse myoblasts and that selective activation of the pathway results in promoter activation of differentiation-specific genes. Moreover, myogenic differentiation is completely blocked when ERK5 expression is inhibited by antisense RNA. Thus, we conclude that the MEK5/ERK5 MAP kinase cascade is critical for early steps of muscle cell differentiation.
Collapse
Affiliation(s)
- D Dinev
- Institut für Medizinische Strahlenkunde und Zellforschung, Universität Würzburg, Versbacher Strasse 5, 97078 Würzburg, Germany
| | | | | | | | | | | | | |
Collapse
|
45
|
Barradeau S, Imaizumi-Scherrer T, Weiss MC, Faust DM. Muscle-regulated expression and determinants for neuromuscular junctional localization of the mouse RIalpha regulatory subunit of cAMP-dependent protein kinase. Proc Natl Acad Sci U S A 2001; 98:5037-42. [PMID: 11296260 PMCID: PMC33159 DOI: 10.1073/pnas.081393598] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2000] [Indexed: 11/18/2022] Open
Abstract
In skeletal muscle, transcription of the gene encoding the mouse type Ialpha (RIalpha) subunit of the cAMP-dependent protein kinase is initiated from the alternative noncoding first exons 1a and 1b. Here, we report that activity of the promoter upstream of exon 1a (Pa) depends on two adjacent E boxes (E1 and E2) in NIH 3T3-transfected fibroblasts as well as in intact muscle. Both basal activity and MyoD transactivation of the Pa promoter require binding of the upstream stimulating factors (USF) to E1. E2 binds either an unknown protein in a USF/E1 complex-dependent manner or MyoD. Both E2-bound proteins seem to function as repressors, but with different strengths, of the USF transactivation potential. Previous work has shown localization of the RIalpha protein at the neuromuscular junction. Using DNA injection into muscle of plasmids encoding segments of RIalpha or RIIalpha fused to green fluorescent protein, we demonstrate that anchoring at the neuromuscular junction is specific to RIalpha subunits and requires the amino-terminal residues 1-81. Mutagenesis of Phe-54 to Ala in the full-length RIalpha-green fluorescent protein template abolishes localization, indicating that dimerization of RIalpha is essential for anchoring. Moreover, two other hydrophobic residues, Val-22 and Ile-27, are crucial for localization of RIalpha at the neuromuscular junction. These amino acids are involved in the interaction of the Caenorhabditis elegans type Ialpha homologue R(CE) with AKAP(CE) and for in vitro binding of RIalpha to dual A-kinase anchoring protein 1. We also show enrichment of dual A-kinase anchoring protein 1 at the neuromuscular junction, suggesting that it could be responsible for RIalpha tethering at this site.
Collapse
Affiliation(s)
- S Barradeau
- Unité de Génétique de la Différenciation, Département de Biologie Moléculaire, Institut Pasteur, Unité de Recherche Associée 1773 du Centre National de la Recherche Scientifique, 25, Rue du Dr Roux, 75724 Paris Cedex 15, France
| | | | | | | |
Collapse
|
46
|
Petkova V, Romanowski MJ, Sulijoadikusumo I, Rohne D, Kang P, Shenk T, Usheva A. Interaction between YY1 and the retinoblastoma protein. Regulation of cell cycle progression in differentiated cells. J Biol Chem 2001; 276:7932-6. [PMID: 11118439 DOI: 10.1074/jbc.m007411200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Overexpression of the transcription factor YY1 activates DNA synthesis in differentiated primary human coronary artery smooth muscle cells. Overexpression of the retinoblastoma protein together with YY1 blocked this effect. In growth-arrested cells, YY1 resides in a complex with the retinoblastoma protein, but the complex is not detected in serum-stimulated S phase cultures, indicating that the interaction of the retinoblastoma protein and YY1 is cell cycle-regulated. Recombinant retinoblastoma protein directly interacts with YY1, destabilizing the interaction of YY1 with DNA and inhibiting its transcription initiator function in vitro. We conclude that in differentiated cells elevation of the nuclear level of YY1 protein favors progression into the S phase, and we propose that this activity is regulated by its interaction with the retinoblastoma protein.
Collapse
Affiliation(s)
- V Petkova
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachuttes 02215, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Lee JJ, Moon YA, Ha JH, Yoon DJ, Ahn YH, Kim KS. Cloning of human acetyl-CoA carboxylase beta promoter and its regulation by muscle regulatory factors. J Biol Chem 2001; 276:2576-85. [PMID: 11076940 DOI: 10.1074/jbc.m007002200] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The 280-kDa beta-isoform of acetyl-CoA carboxylase (ACCbeta) is predominantly expressed in heart and skeletal muscle, whereas the 265-kDa alpha-isoform (ACCalpha) is the major ACC in lipogenic tissues. The ACCbeta promoter showed myoblast-specific promoter activity and was strongly induced by MyoD in NIH3T3 cells. Serial deletions of the promoter revealed that MyoD acts on the E-boxes located at positions -498 to -403 and on the proximal region including the 5'-untranslated region. Destruction of the E-boxes at positions -498 to -403 by site-directed mutagenesis resulted in a significant decrease of MyoD responsiveness. The "TGAAA" at -32 to -28 and the region around the transcription start site play important roles in basal transcription, probably as a TATA box and an Inr element, respectively. Mutations of another E-box at -14 to -9 and a "GCCTGTCA" sequence at +17 to +24 drastically decreased the MyoD responsiveness. The novel cis-element GCCTGTCA was preferentially bound by MyoD homodimer in EMSA and conferred MyoD responsiveness to a luciferase reporter, which was repressed by the overexpression of E12. This finding is unique since activation via E-boxes is mediated by heterodimers of MyoD and E-proteins. We screened a human skeletal muscle cDNA library to isolate clones expressing proteins that bind to the region around the GCCTGTCA (+8 to +27) sequence, and isolated Myf4 and Myf6 cDNAs. Electrophoretic mobility shift assay showed that recombinant Myf4 and Myf6 bind to this novel cis-element. Moreover, transient expression of Myf6 induced significant activation on the ACCbeta promoter or an artificial promoter harboring this novel cis-element. These findings suggest that muscle regulatory factors, such as MyoD, Myf4, and Myf6, contribute to the muscle-specific expression of ACCbeta via E-boxes and the novel cis-element GCCTGTCA.
Collapse
Affiliation(s)
- J J Lee
- Department of Biochemistry and Molecular Biology, the Institute of Genetic Science, Yonsei University College of Medicine, 134 Shinchon-dong Seodaemun-gu, Seoul, 120-752, Korea
| | | | | | | | | | | |
Collapse
|
48
|
Mack CP, Somlyo AV, Hautmann M, Somlyo AP, Owens GK. Smooth muscle differentiation marker gene expression is regulated by RhoA-mediated actin polymerization. J Biol Chem 2001; 276:341-7. [PMID: 11035001 DOI: 10.1074/jbc.m005505200] [Citation(s) in RCA: 307] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Smooth muscle cell (SMC) differentiation is regulated by a complex array of local environmental cues, but the intracellular signaling pathways and the transcription mechanisms that regulate this process are largely unknown. We and others have shown that serum response factor (SRF) contributes to SMC-specific gene transcription, and because the small GTPase RhoA has been shown to regulate SRF, the goal of the present study was to test the hypothesis that RhoA signaling is a critical mechanism for regulating SMC differentiation. Coexpression of constitutively active RhoA in rat aortic SMC cultures significantly increased the activity of the SMC-specific promoters, SM22 and SM alpha-actin, whereas coexpression of C3 transferase abolished the activity of these promoters. Inhibition of either stress fiber formation with the Rho kinase inhibitor Y-27632 (10 microm) or actin polymerization with latrunculin B (0.5 microm) significantly decreased the activity of SM22 and SM alpha-actin promoters. In contrast, increasing actin polymerization with jasplakinolide (0.5 microm) increased SM22 and SM alpha-actin promoter activity by 22-fold and 13-fold, respectively. The above interventions had little or no effect on the transcription of an SRF-dependent c-fos promoter or on a minimal thymidine kinase promoter that is not SRF-dependent. Taken together, the results of these studies indicate that in SMC, RhoA-dependent regulation of the actin cytoskeleton selectively regulates SMC differentiation marker gene expression by modulating SRF-dependent transcription. The results also suggest that RhoA signaling may serve as a convergence point for the multiple signaling pathways that regulate SMC differentiation.
Collapse
MESH Headings
- Actins/metabolism
- Amides/pharmacology
- Animals
- Aorta
- Biomarkers
- Biopolymers/metabolism
- Bridged Bicyclo Compounds, Heterocyclic/pharmacology
- Cell Differentiation
- Cells, Cultured
- Cytochalasin D/pharmacology
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Depsipeptides
- Fluorescent Antibody Technique
- Gene Expression Regulation/drug effects
- Genes, Reporter
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Peptides, Cyclic/pharmacology
- Promoter Regions, Genetic/genetics
- Pyridines/pharmacology
- Rats
- Serum Response Factor
- Signal Transduction
- Stress Fibers/drug effects
- Stress Fibers/metabolism
- Thiazoles/pharmacology
- Thiazolidines
- Transcription, Genetic/drug effects
- Transfection
- rhoA GTP-Binding Protein/antagonists & inhibitors
- rhoA GTP-Binding Protein/metabolism
Collapse
Affiliation(s)
- C P Mack
- Department of Molecular Physiology and Biological Physics, University of Virginia Medical School, Charlottesville, Virginia 22908, USA
| | | | | | | | | |
Collapse
|
49
|
Puri PL, Sartorelli V. Regulation of muscle regulatory factors by DNA-binding, interacting proteins, and post-transcriptional modifications. J Cell Physiol 2000; 185:155-73. [PMID: 11025438 DOI: 10.1002/1097-4652(200011)185:2<155::aid-jcp1>3.0.co;2-z] [Citation(s) in RCA: 230] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Skeletal muscle differentiation is influenced by multiple pathways, which regulate the activity of myogenic regulatory factors (MRFs)-the myogenic basic helix-loop-helix proteins and the MEF2-family members-in positive or negative ways. Here we will review and discuss the network of signals that regulate MRF function during myocyte proliferation, differentiation, and post-mitotic growth. Elucidating the mechanisms governing muscle-specific transcription will provide important insight in better understanding the embryonic development of muscle at the molecular level and will have important implications in setting out strategies aimed at muscle regeneration. Since the activity of MRFs are compromised in tumors of myogenic derivation-the rhabdomyosarcomas-the studies summarized in this review can provide a useful tool to uncover the molecular basis underlying the formation of these tumors.
Collapse
Affiliation(s)
- P L Puri
- Department of Biology, University of California San Diego, La Jolla, California, USA.
| | | |
Collapse
|
50
|
Mikheev AM, Mikheev SA, Zhang Y, Aebersold R, Zarbl H. CArG binding factor A (CBF-A) is involved in transcriptional regulation of the rat Ha-ras promoter. Nucleic Acids Res 2000; 28:3762-70. [PMID: 11000268 PMCID: PMC110773 DOI: 10.1093/nar/28.19.3762] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the present study we identified a positive transcriptional element within the rat Ha-ras promoter previously known as Ha-ras response element (HRE) and identified a trans-acting factor that binds HRE sequences in rat mammary cells. To identify the binding protein we employed sequence specific DNA affinity chromatography. Amino acid sequence analysis of the affinity-purified proteins was performed by tandem mass spectroscopy. The results unexpectedly demonstrated that in rat mammary cells CArG box-binding factor A (CBF-A) is the major protein species that bind specifically to the rat and human HRE sequences with high affinity. The affinity of CBF-A binding to HRE was significantly higher than to the CArG box described as a recognition sequence for CBF-A protein. Transient transfection assays using reporter plasmids verified that mutations within the HRE that disrupt binding of CBF-A also reduced the activity of the rat Ha-ras promoter. Despite the fact that the HRE within the Ha-ras promoter resembles a binding site for Ets transcription factors, we did not detect the binding of Ets-related proteins to the rat HRE in BICR-M1Rk cells. We further demonstrated a correlation between the presence of HRE binding activity and induction of Ha-ras mRNA expression following serum stimulation in the mammary carcinoma cell line. Taken together, our results suggest that CBF-A may play an important role in transcriptional regulation of Ha-ras promoter activity during normal mammary cell growth and carcinogenesis.
Collapse
MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Base Sequence
- Blotting, Western
- Cell Cycle Proteins
- Chromatography, Affinity
- Chromatography, High Pressure Liquid
- DNA/genetics
- DNA/metabolism
- DNA-Binding Proteins/chemistry
- DNA-Binding Proteins/isolation & purification
- DNA-Binding Proteins/metabolism
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, Reporter/genetics
- Genes, ras/genetics
- Heterogeneous-Nuclear Ribonucleoprotein Group A-B
- Humans
- Mass Spectrometry
- Mimosine/pharmacology
- Molecular Sequence Data
- Molecular Weight
- Mutation/genetics
- Promoter Regions, Genetic/genetics
- Protein Binding/drug effects
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-ets
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Repressor Proteins/chemistry
- Repressor Proteins/isolation & purification
- Repressor Proteins/metabolism
- Response Elements/genetics
- Ribonucleoproteins
- Thermodynamics
- Transcription Factors/metabolism
- Transfection
- Tumor Cells, Cultured
- Ultraviolet Rays
Collapse
Affiliation(s)
- A M Mikheev
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Mailstop C1-015, PO Box 19024, Seattle, WA 98104-2092, USA
| | | | | | | | | |
Collapse
|