1
|
Tavera-Montañez C, Hainer SJ, Cangussu D, Gordon SJV, Xiao Y, Reyes-Gutierrez P, Imbalzano AN, Navea JG, Fazzio TG, Padilla-Benavides T. The classic metal-sensing transcription factor MTF1 promotes myogenesis in response to copper. FASEB J 2019; 33:14556-14574. [PMID: 31690123 PMCID: PMC6894080 DOI: 10.1096/fj.201901606r] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/23/2019] [Indexed: 12/15/2022]
Abstract
Metal-regulatory transcription factor 1 (MTF1) is a conserved metal-binding transcription factor in eukaryotes that binds to conserved DNA sequence motifs, termed metal response elements. MTF1 responds to both metal excess and deprivation, protects cells from oxidative and hypoxic stresses, and is required for embryonic development in vertebrates. To examine the role for MTF1 in cell differentiation, we use multiple experimental strategies [including gene knockdown (KD) mediated by small hairpin RNA and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9), immunofluorescence, chromatin immunopreciptation sequencing, subcellular fractionation, and atomic absorbance spectroscopy] and report a previously unappreciated role for MTF1 and copper (Cu) in cell differentiation. Upon initiation of myogenesis from primary myoblasts, both MTF1 expression and nuclear localization increased. Mtf1 KD impaired differentiation, whereas addition of nontoxic concentrations of Cu+-enhanced MTF1 expression and promoted myogenesis. Furthermore, we observed that Cu+ binds stoichiometrically to a C terminus tetra-cysteine of MTF1. MTF1 bound to chromatin at the promoter regions of myogenic genes, and Cu addition stimulated this binding. Of note, MTF1 formed a complex with myogenic differentiation (MYOD)1, the master transcriptional regulator of the myogenic lineage, at myogenic promoters. These findings uncover unexpected mechanisms by which Cu and MTF1 regulate gene expression during myoblast differentiation.-Tavera-Montañez, C., Hainer, S. J., Cangussu, D., Gordon, S. J. V., Xiao, Y., Reyes-Gutierrez, P., Imbalzano, A. N., Navea, J. G., Fazzio, T. G., Padilla-Benavides, T. The classic metal-sensing transcription factor MTF1 promotes myogenesis in response to copper.
Collapse
Affiliation(s)
- Cristina Tavera-Montañez
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Sarah J. Hainer
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and
| | - Daniella Cangussu
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Shellaina J. V. Gordon
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Yao Xiao
- Department of Chemistry, Skidmore College, Saratoga Springs, New York, USA
| | - Pablo Reyes-Gutierrez
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Anthony N. Imbalzano
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Juan G. Navea
- Department of Chemistry, Skidmore College, Saratoga Springs, New York, USA
| | - Thomas G. Fazzio
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and
| | - Teresita Padilla-Benavides
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| |
Collapse
|
2
|
Noguchi YT, Nakamura M, Hino N, Nogami J, Tsuji S, Sato T, Zhang L, Tsujikawa K, Tanaka T, Izawa K, Okada Y, Doi T, Kokubo H, Harada A, Uezumi A, Gessler M, Ohkawa Y, Fukada SI. Cell-autonomous and redundant roles of Hey1 and HeyL in muscle stem cells: HeyL requires Hes1 to bind diverse DNA sites. Development 2019; 146:dev.163618. [DOI: 10.1242/dev.163618] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 01/31/2019] [Indexed: 12/20/2022]
Abstract
The undifferentiated state of muscle stem (satellite) cells (MuSCs) is maintained by the canonical Notch pathway. Although three bHLH transcriptional factors, Hey1, HeyL, and Hes1, are considered to be potential effectors of the Notch pathway exerting anti-myogenic effects, neither HeyL nor Hes1 inhibits myogenic differentiation of myogenic cell lines. Furthermore, whether these factors work redundantly or cooperatively is unknown. Here, we showed cell-autonomous functions of Hey1 and HeyL in MuSCs using conditional and genetic null mice. Analysis of cultured MuSCs revealed anti-myogenic activity of both HeyL and Hes1. We found that HeyL forms heterodimeric complexes with Hes1 in living cells. Moreover, our ChIP-Seq experiments demonstrated that, compared with HeyL alone, HeyL-Hes1 heterodimer bound with high affinity to specific sites in the chromatin including the cis-element of Hey1. Finally, the analyses of myogenin promoter activity showed that HeyL and Hes1 acted synergistically to suppress myogenic differentiation. Collectively, those results suggest that HeyL and Hey1 function redundantly in MuSCs, and that HeyL requires Hes1 for effective DNA binding and biological activity.
Collapse
Affiliation(s)
- Yu-taro Noguchi
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Miki Nakamura
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Nobumasa Hino
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Jumpei Nogami
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Sayaka Tsuji
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takahiko Sato
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Lidan Zhang
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kazutake Tsujikawa
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toru Tanaka
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kohei Izawa
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoshiaki Okada
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takefumi Doi
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroki Kokubo
- Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8551, Japan
| | - Akihito Harada
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Akiyoshi Uezumi
- Department of Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
| | - Manfred Gessler
- Developmental Biochemistry, Theodor-Boveri-Institute / Biocenter, and Comprehensive Cancer Center Mainfranken, University of Wuerzburg, 97074 Wuerzburg, Germany
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - So-ichiro Fukada
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| |
Collapse
|
3
|
Kurisaki T, Masuda A, Nakagiri S, Hayata Y, Kuhara M, Kishi Y, Sehara-Fujisawa A. Generation of a monoclonal antibody reactive to prefusion myocytes. J Muscle Res Cell Motil 2011; 32:31-8. [PMID: 21597958 PMCID: PMC3141826 DOI: 10.1007/s10974-011-9247-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 04/26/2011] [Indexed: 11/30/2022]
Abstract
We established a novel monoclonal antibody, Yaksa that is specific to a subpopulation of myogenic cells. The Yaksa antigen is not expressed on the surface of growing myoblasts but only on a subpopulation of myogenin-positive myocytes. When Yaksa antigen-positive mononucleated cells were freshly prepared from a murine myogenic cell by a cell sorter, they fused with each other and formed multinucleated myotubes shortly after replating while Yaksa antigen-negative cells scarcely generated myotubes. These results suggest that Yaksa could segregate fusion-competent, mononucleated cells from fusion–incompetent cells during muscle differentiation. The Yaksa antigen was also expressed in developing muscle and regenerating muscle in vivo and it was localized at sites of cell–cell contact between mono-nucleated muscle cells and between mono-nucleated muscle cells and myotubes. Thus, Yaksa that marks prefusion myocytes before myotube formation can be a useful tool to elucidate the cellular and molecular mechanisms of myogenic cell fusion.
Collapse
Affiliation(s)
- Tomohiro Kurisaki
- Field of Growth Regulation, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
| | | | | | | | | | | | | |
Collapse
|
4
|
Yanagisawa M, Mukai A, Shiomi K, Song SY, Hashimoto N. Community effect triggers terminal differentiation of myogenic cells derived from muscle satellite cells by quenching Smad signaling. Exp Cell Res 2011; 317:221-33. [DOI: 10.1016/j.yexcr.2010.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Revised: 09/16/2010] [Accepted: 10/13/2010] [Indexed: 12/23/2022]
|
5
|
Okabe Y, Sano T, Nagata S. Regulation of the innate immune response by threonine-phosphatase of Eyes absent. Nature 2009; 460:520-4. [PMID: 19561593 DOI: 10.1038/nature08138] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Accepted: 05/08/2009] [Indexed: 11/09/2022]
Abstract
Innate immunity is stimulated not only by viral or bacterial components, but also by non-microbial danger signals (damage-associated molecular patterns). One of the damage-associated molecular patterns is chromosomal DNA that escapes degradation. In programmed cell death and erythropoiesis, DNA from dead cells or nuclei expelled from erythroblasts is digested by DNase II in the macrophages after they are engulfed. DNase II(-/-) (also known as Dnase2a(-/-)) mice suffer from severe anaemia or chronic arthritis due to interferon-beta (IFN-beta) and tumour necrosis factor-alpha (TNF-alpha) produced from the macrophages carrying undigested DNA in a Toll-like receptor (TLR)-independent mechanism. Here we show that Eyes absent 4 (EYA4), originally identified as a co-transcription factor, stimulates the expression of IFN-beta and CXCL10 in response to the undigested DNA of apoptotic cells. EYA4 enhanced the innate immune response against viruses (Newcastle disease virus and vesicular stomatitis virus), and could associate with signalling molecules (IPS-1 (also known as MAVS), STING (TMEM173) and NLRX1). Three groups have previously shown that EYA has phosphatase activity. We found that mouse EYA family members act as a phosphatase for both phosphotyrosine and phosphothreonine. The haloacid dehalogenase domain at the carboxy terminus contained the tyrosine-phosphatase, and the amino-terminal half carried the threonine-phosphatase. Mutations of the threonine-phosphatase, but not the tyrosine-phosphatase, abolished the ability of EYA4 to enhance the innate immune response, suggesting that EYA regulates the innate immune response by modulating the phosphorylation state of signal transducers for the intracellular pathogens.
Collapse
Affiliation(s)
- Yasutaka Okabe
- Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Yoshida-Konoe, Kyoto 606-8501, Japan
| | | | | |
Collapse
|
6
|
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
|
7
|
OSONOI M, ITO K, TAKAHASHI J. Expression of the Myogenin-LacZ Reporter Gene Introduced into Embryonic Stem(ES) Cells In Vitro. J Reprod Dev 2001. [DOI: 10.1262/jrd.47.45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Makoto OSONOI
- Laboratory of Animal Breeding and Reproduction, Faculty of Agriculture, Iwate University
| | - Kazuei ITO
- Laboratory of Animal Breeding and Reproduction, Faculty of Agriculture, Iwate University
| | - Jutaro TAKAHASHI
- Laboratory of Animal Breeding and Reproduction, Faculty of Agriculture, Iwate University
| |
Collapse
|
8
|
Ohto H, Kamada S, Tago K, Tominaga SI, Ozaki H, Sato S, Kawakami K. Cooperation of six and eya in activation of their target genes through nuclear translocation of Eya. Mol Cell Biol 1999; 19:6815-24. [PMID: 10490620 PMCID: PMC84678 DOI: 10.1128/mcb.19.10.6815] [Citation(s) in RCA: 249] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drosophila sine oculis and eyes absent genes synergize in compound-eye formation. The murine homologues of these genes, Six and Eya, respectively, show overlapping expression patterns during development. We hypothesized that Six and Eya proteins cooperate to regulate their target genes. Cotransfection assays were performed with various combinations of Six and Eya to assess their effects on a potential natural target, myogenin promoter, and on a synthetic promoter, the thymidine kinase gene promoter fused to multimerized Six4 binding sites. A clear synergistic activation of these promoters was observed in certain combinations of Six and Eya. To investigate the molecular basis for the cooperation, we first examined the intracellular distribution of Six and Eya proteins in transfected COS7 cells. Coexpression of Six2, Six4, or Six5 induced nuclear translocation of Eya1, Eya2, and Eya3, which were otherwise distributed in the cytoplasm. In contrast, coexpression of Six3 did not result in nuclear localization of any Eya proteins. Six and Eya proteins were coimmunoprecipitated from nuclear extracts prepared from cotransfected COS7 cells and from rat liver. Six domain and homeodomain, two evolutionarily conserved domains among various Six proteins, were necessary and sufficient for the nuclear translocation of Eya. In contrast, the Eya domain, a conserved domain among Eya proteins, was not sufficient for the translocation. A specific interaction between the Six domain and homeodomain of Six4 and Eya2 was observed by yeast two-hybrid analysis. Our results suggest that transcription regulation of certain target genes by Six proteins requires cooperative interaction with Eya proteins: complex formation through direct interaction and nuclear translocation of Eya proteins. This implies that the synergistic action of Six and Eya is conserved in the mouse and is mediated through cooperative activation of their target genes.
Collapse
Affiliation(s)
- H Ohto
- Departments of Biology, Jichi Medical School, Tochigi 329-0498, Japan
| | | | | | | | | | | | | |
Collapse
|
9
|
Affiliation(s)
- A Faerman
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
| | | |
Collapse
|
10
|
Yamamoto N, Akiyama S, Katagiri T, Namiki M, Kurokawa T, Suda T. Smad1 and smad5 act downstream of intracellular signalings of BMP-2 that inhibits myogenic differentiation and induces osteoblast differentiation in C2C12 myoblasts. Biochem Biophys Res Commun 1997; 238:574-80. [PMID: 9299554 DOI: 10.1006/bbrc.1997.7325] [Citation(s) in RCA: 179] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bone morphogenetic protein-2 (BMP-2) inhibits terminal differentiation of C2C12 myoblasts and converts them into osteoblast lineage cells (Katagiri, T., Yamaguchi, A., Komaki, M., Abe, E., Takahashi, N., Ikeda, T., Rosen, V., Wozney, J. M., Fujisawa-Sehara, A., and Suda T. (1994) J. Cell Biol. 127, 1755-1766). In the present study, we examined the possible involvement of Smad proteins, vertebrate homologues of Drosophila Mothers against decapentaplegic, in the BMP effects on the differentiation of C2C12 myoblasts. C2C12 cells expressed Smad1, Smad2, Smad4, and Smad5 mRNAs, and expression levels were not altered by treatment with BMP-2 or TGF-beta1. When Smads were transiently transfected into C2C12 cells, both Smad1 and Smad5 induced alkaline phosphatase (ALP) activity and decreased the activity of myogenin promoter/chloramphenicol acetyltransferase (myogenin-CAT) without BMP-2. When C-terminal-truncated Smad1 and Smad5 were transfected into constitutively active BMP receptor type IB (BMPR-IB)-expressing C2C12 cells, BMP signals were blocked, resulting in an increase in myogenin-CAT activity. On the other hand, Smad1 and Smad5 decreased myogenin-CAT activity but did not induce ALP activity in MyoD-transfected NIH3T3 fibroblasts. These results suggest that both Smad1 and Smad5 are involved in the intracellular BMP signals which inhibit myogenic differentiation and induce osteoblast differentiation in C2C12 cells, and that the conversion of the two differentiation pathways is regulated independently at a transcriptional level.
Collapse
Affiliation(s)
- N Yamamoto
- School of Dentistry, Showa University, Tokyo, 142, Japan
| | | | | | | | | | | |
Collapse
|
11
|
Huang J, Blackwell TK, Kedes L, Weintraub H. Differences between MyoD DNA binding and activation site requirements revealed by functional random sequence selection. Mol Cell Biol 1996; 16:3893-900. [PMID: 8668207 PMCID: PMC231386 DOI: 10.1128/mcb.16.7.3893] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A method has been developed for selecting functional enhancer/promoter sites from random DNA sequences in higher eukaryotic cells. Of sequences that were thus selected for transcriptional activation by the muscle-specific basic helix-loop-helix protein MyoD, only a subset are similar to the preferred in vitro binding consensus, and in the same promoter context an optimal in vitro binding site was inactive. Other sequences with full transcriptional activity instead exhibit sequence preferences that, remarkably, are generally either identical or very similar to those found in naturally occurring muscle-specific promoters. This first systematic examination of the relation between DNA binding and transcriptional activation by basic helix-loop-helix proteins indicates that binding per se is necessary but not sufficient for transcriptional activation by MyoD and implies a requirement for other DNA sequence-dependent interactions or conformations at its binding site.
Collapse
Affiliation(s)
- J Huang
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA
| | | | | | | |
Collapse
|
12
|
Cheng TC, Tseng BS, Merlie JP, Klein WH, Olson EN. Activation of the myogenin promoter during mouse embryogenesis in the absence of positive autoregulation. Proc Natl Acad Sci U S A 1995; 92:561-5. [PMID: 7831329 PMCID: PMC42781 DOI: 10.1073/pnas.92.2.561] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Myogenin, a member of the MyoD family of helix-loop-helix proteins, can induce myogenesis in a wide range of cell types. In addition to activating muscle structural genes, members of the MyoD family can autoactivate their own and cross-activate one another's expression in transfected cells. This has led to the hypothesis that autoregulatory loops among these factors provide a mechanism for amplifying and maintaining the muscle-specific gene expression program in vivo. Here, we make use of myogenin-null mice to directly test this hypothesis. To investigate whether the myogenin protein autoregulates the myogenin gene during embryogenesis, we introduced a myogenin-lacZ transgene into mice harboring a null mutation at the myogenin locus. Despite a severe deficiency of skeletal muscle in myogenin-null neonates, the myogenin-lacZ transgene was expressed normally in myogenic cells throughout embryogenesis. These results show that myogenin is not required for regulation of the myogenin gene and argue against the existence of a myogenin autoregulatory loop in the embryo.
Collapse
Affiliation(s)
- T C Cheng
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030
| | | | | | | | | |
Collapse
|
13
|
KIM SY, TAKAHASHI J, TSUTSUMI KI, KANG MS, YASUDA Y. Expression of the Myogenin-LacZ Reporter Gene During Early Postimplantation Development of the Mouse. J Reprod Dev 1995. [DOI: 10.1262/jrd.41.241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Sang-Yong KIM
- Laboratory of Animal Breeding, Iwate University, Morioka 020, Japan
| | - Jutaro TAKAHASHI
- Laboratory of Animal Breeding, Iwate University, Morioka 020, Japan
| | - Ken-ichi TSUTSUMI
- Institute for Cell Biology and Genetics, Faculty of Agriculture, Iwate University, Morioka 020, Japan
| | - Min-Soo KANG
- College of Agriculture, Cheju National University, Cheju 690-753, Korea
| | - Yasuhisa YASUDA
- Laboratory of Animal Breeding, Iwate University, Morioka 020, Japan
| |
Collapse
|