Myocyte nuclear factor, a novel winged-helix transcription factor under both developmental and neural regulation in striated myocytes

A sequence motif (CCAC box) within an upstream enhancer region of the human myoglobin gene is essential for transcriptional activity in both cardiac and skeletal muscle. A cDNA clone, myocyte nuclear factor (MNF), was isolated from a murine expression library on the basis of sequence-specific binding to the myoglobin CCAC box motif and was found to encode a novel member of the winged-helix or HNF-3/fork head family of transcription factors. Probes based on this sequence identify two mRNA species that are upregulated during myocyte differentiation, and antibodies raised against recombinant MNF identify proteins of approximately 90, 68, and 65 kDa whose expression is regulated following differentiation of myogenic cells in culture. In addition, the 90-kDa form of MNF is phosphorylated and is upregulated in intact muscles subjected to chronic motor nerve stimulation, a potent stimulus to myoglobin gene regulation. Amino acid residues 280 to 389 of MNF demonstrate 35 to 89% sequence identity to the winged-helix domain from other known members of this family, but MNF is otherwise divergent. A proline-rich amino-terminal region (residues 1 to 206) of MNF functions as a transcriptional activation domain. These studies provide the first evidence that members of the winged-helix family of transcription factors have a role in myogenic differentiation and in remodeling processes of adult muscles that occur in response to physiological stimuli.

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Hepatocyte nuclear factor 3 beta contains two transcriptional activation domains, one of which is novel and conserved with the Drosophila fork head protein

Molecular and Cellular Biology ◽

10.1128/mcb.12.9.3723-3732.1992 ◽

1992 ◽

Vol 12 (9) ◽

pp. 3723-3732

Author(s):

L Pani ◽

D G Overdier ◽

A Porcella ◽

X Qian ◽

E Lai ◽

...

Keyword(s):

Amino Acids ◽

Transcription Factors ◽

Transcriptional Activation ◽

Carboxyl Terminus ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Amino Terminal ◽

Fork Head ◽

Fourth Segment ◽

Region Ii

The hepatocyte nuclear factor 3 (HNF-3) gene family is composed of three proteins (alpha, beta, and gamma) that are transcription factors involved in the coordinate expression of several liver genes. All three proteins share strong homology in their DNA binding domains (region I) and are able to recognize the same DNA sequence. They also possess two similar stretches of amino acids at the carboxyl terminus (regions II and III) and a fourth segment of homology at the amino terminus (region IV). Furthermore, the HNF-3 proteins demonstrate homology with the Drosophila homeotic gene fork head in regions I, II, and III, suggesting that HNF-3 may be its mammalian homolog. In order to define HNF-3 beta protein domains involved in transcriptional activation, we have used a reporter gene, whose transcription is dependent on HNF-3 binding, for hepatoma cell cotransfection assays with expression vectors that produced different truncated HNF-3 beta proteins. A position-independent activation domain which contained conserved regions II and III was identified at the carboxyl terminus of the HNF-3 beta protein (amino acids 361 to 458). Moreover, site-directed mutations that altered the sequences within regions II and III demonstrated their importance to transactivation. The region II-III domain does not possess amino acid sequences in common with other transcription factors and may define a novel activation motif. HNF-3 beta amino-terminal sequences defined by conserved region IV also contributed to transactivation, but region IV activity required the participation of the region II-III domain. Region IV is abundant in serine amino acids and contains two putative casein kinase I phosphorylation sites, a feature similar to protein motifs described for the transcription factors Pit-1/GHF-1 and HNF-1.

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Hepatocyte nuclear factor 3 beta contains two transcriptional activation domains, one of which is novel and conserved with the Drosophila fork head protein.

Molecular and Cellular Biology ◽

10.1128/mcb.12.9.3723 ◽

1992 ◽

Vol 12 (9) ◽

pp. 3723-3732 ◽

Cited By ~ 112

Author(s):

L Pani ◽

D G Overdier ◽

A Porcella ◽

X Qian ◽

E Lai ◽

...

Keyword(s):

Amino Acids ◽

Transcription Factors ◽

Transcriptional Activation ◽

Carboxyl Terminus ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Amino Terminal ◽

Fork Head ◽

Fourth Segment ◽

Region Ii

The hepatocyte nuclear factor 3 (HNF-3) gene family is composed of three proteins (alpha, beta, and gamma) that are transcription factors involved in the coordinate expression of several liver genes. All three proteins share strong homology in their DNA binding domains (region I) and are able to recognize the same DNA sequence. They also possess two similar stretches of amino acids at the carboxyl terminus (regions II and III) and a fourth segment of homology at the amino terminus (region IV). Furthermore, the HNF-3 proteins demonstrate homology with the Drosophila homeotic gene fork head in regions I, II, and III, suggesting that HNF-3 may be its mammalian homolog. In order to define HNF-3 beta protein domains involved in transcriptional activation, we have used a reporter gene, whose transcription is dependent on HNF-3 binding, for hepatoma cell cotransfection assays with expression vectors that produced different truncated HNF-3 beta proteins. A position-independent activation domain which contained conserved regions II and III was identified at the carboxyl terminus of the HNF-3 beta protein (amino acids 361 to 458). Moreover, site-directed mutations that altered the sequences within regions II and III demonstrated their importance to transactivation. The region II-III domain does not possess amino acid sequences in common with other transcription factors and may define a novel activation motif. HNF-3 beta amino-terminal sequences defined by conserved region IV also contributed to transactivation, but region IV activity required the participation of the region II-III domain. Region IV is abundant in serine amino acids and contains two putative casein kinase I phosphorylation sites, a feature similar to protein motifs described for the transcription factors Pit-1/GHF-1 and HNF-1.

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Neisseria gonorrhoeae Epithelial Cell Interaction Leads to the Activation of the Transcription Factors Nuclear Factor κB and Activator Protein 1 and the Induction of Inflammatory Cytokines

Journal of Experimental Medicine ◽

10.1084/jem.186.2.247 ◽

1997 ◽

Vol 186 (2) ◽

pp. 247-258 ◽

Cited By ~ 107

Author(s):

Michael Naumann ◽

Silja Weßler ◽

Cornelia Bartsch ◽

Björn Wieland ◽

Thomas F. Meyer

Keyword(s):

Transcription Factors ◽

Epithelial Cells ◽

Neisseria Gonorrhoeae ◽

Transcriptional Activation ◽

Inflammatory Cytokine ◽

Nuclear Factor ◽

Activator Protein 1 ◽

Messenger Rnas ◽

Basic Leucine Zipper ◽

Activator Protein

We have studied the effect of human bacterial pathogen Neisseria gonorrhoeae (Ngo) on the activation of nuclear factor (NF)-κB and the transcriptional activation of inflammatory cytokine genes upon infection of epithelial cells. During the course of infection, Ngo, the etiologic agent of gonorrhea, adheres to and penetrates mucosal epithelial cells. In vivo, localized gonococcal infections are often associated with a massive inflammatory response. We observed upregulation of several inflammatory cytokine messenger RNAs (mRNAs) and the release of the proteins in Ngo-infected epithelial cells. Moreover, infection with Ngo induced the formation of a NF-κB DNA–protein complex and, with a delay in time, the activation of activator protein 1, whereas basic leucine zipper transcription factors binding to the cAMP-responsive element or CAAT/enhancer-binding protein DNA-binding sites were not activated. In supershift assays using NF-κB–specific antibodies, we identified a NF-κB p50/p65 heterodimer. The NF-κB complex was formed within 10 min after infection and decreased 90 min after infection. Synthesis of tumor necrosis factor α and interluekin (IL)-1β occurred at later times and therefore did not account for NF-κB activation. An analysis of transiently transfected IL-6 promoter deletion constructs suggests that NF-κB plays a crucial role for the transcriptional activation of the IL-6 promoter upon Ngo infection. Inactivation of NF-κB conferred by the protease inhibitor N-tosyl-l-phenylalanine chloromethyl ketone inhibited mRNA upregulation of most, but not all, studied cyctokine genes. Activation of NF-κB and cytokine mRNA upregulation also occur in Ngo-infected epithelial cells that were treated with cytochalasin D, indicating an extracellular signaling induced before invasion.

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Transcriptional activation of the chicken lysozyme gene by NF-κ Bp65 (RelA) and c-Rel, but not by NF-κ Bp50

Biochemical Journal ◽

10.1042/bj3130039 ◽

1996 ◽

Vol 313 (1) ◽

pp. 39-44 ◽

Cited By ~ 25

Author(s):

Loc VAN PHI

Keyword(s):

Transcription Factors ◽

Transcriptional Activation ◽

Nuclear Factor Kappa B ◽

Protein Complexes ◽

Terminal Differentiation ◽

Binding Activity ◽

Nuclear Factor ◽

Lysozyme Gene ◽

Chloramphenicol Acetyltransferase Gene ◽

Chicken Lysozyme

The lysozyme gene is expressed at a low level in myeloblasts and is progressively activated to constitutively high expression in mature macrophages. The binding activity of the newly defined NF-ĸB/Rel family of transcription factors increases during the terminal differentiation of macrophages. In this study, I show that NF-ĸB/Rel-like proteins bind to the nuclear factor kappa B (ĸB)-like sequence of the lysozyme promoter. These binding activities were induced by treatment of HD11 cells with lipopolysaccharide. Immunomobility shift assays show that c-Rel is possibly a factor in the complexes that bind to the ĸB-like sequence lysĸB. Binding activity to one of the protein complexes seems to be regulated by phosphorylation. In fact, overexpression of p65 and c-Rel stimulates expression of the chloramphenicol acetyltransferase gene controlled by the lysozyme promoter. Furthermore, co-transfection experiments reveal that the ĸB-like sequence within the lysozyme promoter mediates the transactivation by p65 and c-Rel. These results indicate that the p65 and c-Rel could be components of the protein complexes that bind to the ĸB-like sequence and this binding could contribute to the progressively activated expression of the lysozyme gene during the terminal differentiation of macrophages.

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Negative regulation of nuclear factor-kappaB activation and function by glucocorticoids

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0280069 ◽

2002 ◽

Vol 28 (2) ◽

pp. 69-78 ◽

Cited By ~ 157

Author(s):

WY Almawi ◽

OK Melemedjian

Keyword(s):

Transcription Factors ◽

Transcriptional Activation ◽

Promoter Region ◽

Nuclear Translocation ◽

Nuclear Factor Kappab ◽

Nuclear Factor ◽

Creb Binding Protein ◽

Transcriptional Initiation ◽

Nf Kappab ◽

And Function

Glucocorticoids (GCs) exert their anti-inflammatory and antiproliferative effects principally by inhibiting the expression of cytokines and adhesion molecules. Mechanistically, GCs diffuse through the cell membrane, and bind to their inactive cytosolic receptors (GRs), which then undergo conformational modifications that allow for their nuclear translocation. In the nucleus, activated GRs modulate transcriptional events by directly associating with DNA elements, compatible with the GCs response elements (GRE) motif, and located in variable copy numbers and at variable distances from the TATA box, in the promoter region of GC-responsive genes. In addition, activated GRs also acted by antagonizing the activity of transcription factors, in particular nuclear factor-kappaB (NF-kappaB), by direct and indirect mechanisms. GCs induced gene transcription and protein synthesis of the NF-kappaB inhibitor, IkappaB. Activated GR also antagonized NF-kappaB activity through protein-protein interaction involving direct complexing with, and inhibition of, NF-kappaB binding to DNA (Simple Model), or association with NF-kappaB bound to the kappaB DNA site (Composite Model). In addition, and according to the Transmodulation Model, GRE-bound GR may interact with and inhibit the activity of kappaB-bound NF-kappaB via a mechanism involving cross-talk between the two transcription factors. Lastly, GR may compete with NF-kappaB for nuclear coactivators, including CREB binding protein and p300, thereby reducing and inhibiting transcriptional activation by NF-kappaB. It should be noted that, in exerting its effect, activated GR did not affect the correct assembly of the pre-initiation (DAB) complex, but acted rather more proximally in inhibiting the correct assembly of transcription factors in the promoter region, and thus transcriptional initiation.

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The winged-helix/forkhead protein myocyte nuclear factor β (MNF-β) forms a co-repressor complex with mammalian Sin3B

Biochemical Journal ◽

10.1042/bj3450335 ◽

2000 ◽

Vol 345 (2) ◽

pp. 335-343 ◽

Cited By ~ 33

Author(s):

Quan YANG ◽

Yanfeng KONG ◽

Beverly ROTHERMEL ◽

Daniel J. GARRY ◽

Rhonda BASSEL-DUBY ◽

...

Keyword(s):

Gene Family ◽

Transcriptional Repression ◽

Growth Regulation ◽

Cellular Proliferation ◽

Precursor Cells ◽

Nuclear Factor ◽

Winged Helix ◽

Repressor Complex ◽

Myocyte Nuclear Factor ◽

Myogenic Precursor

Winged-helix/forkhead proteins regulate developmental events in both invertebrate and vertebrate organisms, but biochemical functions that establish a mechanism of action have been defined for only a few members of this extensive gene family. Here we demonstrate that MNF (myocyte nuclear factor)-β, a winged-helix protein expressed selectively and transiently in myogenic precursor cells of the heart and skeletal muscles, collaborates with proteins of the mammalian Sin3 (mSin3) family to repress transcription. Mutated forms of MNF-β that fail to bind mSin3 are defective in transcriptional repression and in negative growth regulation, an overexpression phenotype revealed in oncogenic transformation assays. These data extend the known repertoire of transcription factors with which mSin3 proteins can function as co-repressors to include members of the winged-helix gene family. Transcriptional repression by MNF-β-mSin3 complexes may contribute to the co-ordination of cellular proliferation and terminal differentiation of myogenic precursor cells.

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Murine chromosomal location of eight members of the hepatocyte nuclear factor 3/fork head winged helix family of transcription factors

Genomics ◽

10.1016/0888-7543(95)80038-n ◽

1995 ◽

Vol 25 (2) ◽

pp. 388-393 ◽

Cited By ~ 17

Author(s):

Karen B. Avraham ◽

Colin Fletcher ◽

David G. Overdier ◽

Derek E. Clevidence ◽

Eseng Lai ◽

...

Keyword(s):

Transcription Factors ◽

Chromosomal Location ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Winged Helix ◽

Fork Head

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The winged-helix/forkhead protein myocyte nuclear factor β (MNF-β) forms a co-repressor complex with mammalian Sin3B

Biochemical Journal ◽

10.1042/0264-6021:3450335 ◽

2000 ◽

Vol 345 (2) ◽

pp. 335 ◽

Cited By ~ 18

Author(s):

Quan YANG ◽

Yanfeng KONG ◽

Beverly ROTHERMEL ◽

Daniel J. GARRY ◽

Rhonda BASSEL-DUBY ◽

...

Keyword(s):

Nuclear Factor ◽

Winged Helix ◽

Repressor Complex ◽

Myocyte Nuclear Factor

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The adenovirus E1A-regulated transcription factor E4F is generated from the human homolog of nuclear factor phiAP3.

Molecular and Cellular Biology ◽

10.1128/mcb.17.4.1890 ◽

1997 ◽

Vol 17 (4) ◽

pp. 1890-1903 ◽

Cited By ~ 20

Author(s):

E R Fernandes ◽

R J Rooney

Keyword(s):

Dna Binding ◽

Transcriptional Activation ◽

Binding Activity ◽

Full Length ◽

Nuclear Factor ◽

Human Homolog ◽

Amino Terminal ◽

Dna Binding Activity ◽

Terminal Fragment ◽

Amino Terminal Fragment

A 50-kDa cellular factor, E4F, has been implicated in mediating trans activation of the adenovirus E4 gene by the 289R E1A(13S) protein. Previous experiments demonstrated an E1A-dependent increase in E4F DNA binding activity, dependent on phosphorylation, that correlated with the activation of E4 transcription. Using expression screening, we isolated a cDNA clone encoding the E4F protein, as judged by DNA binding characteristics, transcriptional activation, and immunological criteria. The E4F-1 cDNA encodes a 783-amino-acid polypeptide that has 86% sequence identity with the murine nuclear factor phiAP3, a GLI-krüppel-related protein. E4F DNA binding activity is encoded within an amino-terminal region of E4F-1 that contains a zinc finger domain and, as with endogenous E4F, is phosphatase sensitive. We found that E4F was generated from the full-length E4F-1-encoded protein as a 50-kDa amino-terminal fragment. Moreover, E1A(13S) expression induced the phosphorylation of both forms of E4F-1 but differentially regulated their DNA binding activities, stimulating the 50-kDa fragment while reducing the activity of the full-length protein. In transient-transfection assays, the E4F-1 amino-terminal fragment stimulated the adenovirus E4 promoter in the presence of E1A(13S), whereas the full-length protein repressed the promoter in the absence, but not the presence, of E1A. The results indicate that the 50-kDa polypeptide responsible for E4F DNA binding activity is a fragment generated from the human homolog of phiAP3 and that the two forms of the E4F-1 protein are differentially regulated by E1A through phosphorylation.

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