scholarly journals Insulin and dexamethasone induce GLUT4 gene expression in foetal brown adipocytes: synergistic effect through CCAAT/enhancer-binding protein alpha

2003 ◽  
Vol 372 (2) ◽  
pp. 617-624 ◽  
Author(s):  
Rosario HERNANDEZ ◽  
Teresa TERUEL ◽  
Margarita LORENZO
Keyword(s):  
Dna Binding ◽  
Synergistic Effect ◽  
Glucose Uptake ◽  
Binding Protein ◽  
Fold Increase ◽  
Binding Activity ◽  
Brown Adipocytes ◽  
Dna Binding Activity ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

Treatment of foetal brown adipocytes in primary culture with either dexamethasone or insulin, at physiological concentrations, for 24 h up-regulates the expression of the GLUT4 gene, producing a synergistic effect on mRNA accumulation (20-fold increase), in the amount of protein in the total membrane fraction (8-fold increase) and in the transactivation of a full-promoter GLUT4-chloramphenicol acetyltransferase gene (CAT) construct (7-fold increase). However, GLUT1 expression remains essentially unmodified regardless of the presence of the hormones. As a consequence, exposure of brown adipocytes to dexamethasone and insulin results in a dramatic increase of glucose uptake (12-fold). Dexamethasone induces the expression of CCAAT/enhancer-binding protein (C/EBP) α, insulin promotes myocyte enhancer factor-2 DNA-binding activity and both combined produces a significant increase in C/EBPα DNA-binding activity. Moreover, co-transfection with a wild-type C/EBPα construct transactivates a full-promoter GLUT4-CAT fusion gene, whereas a dominant-negative C/EBPα expression vector impairs the hormonal effects. Our results show that the synergism between insulin and glucocorticoids on glucose uptake is a consequence of the activation of the GLUT4 promoter by the transcription factor C/EBPα.

scholarly journals Expression of the genes encoding CCAAT-enhancer binding protein isoforms in the mouse mammary gland during lactation and involution

1998 ◽  
Vol 334 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Georgios SABATAKOS ◽  
Gareth E. DAVIES ◽  
Maria GROSSE ◽  
Anthony CRYER ◽  
Dipak P. RAMJI
Keyword(s):  
Transcription Factors ◽  
Mammary Gland ◽  
Dna Binding ◽  
Binding Protein ◽  
Mouse Mammary Gland ◽  
Binding Activity ◽  
Protein Isoforms ◽  
Dna Binding Activity ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

Transcription factors belonging to the CCAAT-enhancer binding protein (C/EBP) family have been implicated in the activation of gene expression in the mammary gland during lactation. We have therefore investigated the detailed expression profile of the C/EBP family during lactation and involution of the mouse mammary gland. The expression of C/EBPβ and C/EBPδ mRNA was low during lactation, increased dramatically at the beginning of involution and remained constant thereafter. In contrast, C/EBPα mRNA expression was relatively high during the early stages of lactation, declined to low levels during the late stages of lactation and at the start of involution, and increased again during involution. Electrophoretic mobility-shift assays showed a close correlation between the expression of the C/EBP genes and the functional C/EBP DNA-binding activity and, additionally, demonstrated the participation of heterodimers, formed from among the three proteins, in DNA–protein interactions. The DNA-binding activity of the activator protein 1 (AP1) family of transcription factors was also induced during involution. These results therefore point to potentially important regulatory roles for both the C/EBP and the AP1 family during lactation and involution of the mammary gland.

UV stimulation induces nuclear factor κB (NF-κB) DNA-binding activity but not transcriptional activation

2001 ◽  
Vol 29 (6) ◽  
pp. 688-691 ◽  
Author(s):  
K. J. Campbell ◽  
N. R. Chapman ◽  
N. D. Perkins
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Cellular Response ◽  
Uv Light ◽  
Binding Protein ◽  
Nuclear Factor Κb ◽  
Camp Response Element Binding ◽  
Binding Activity ◽  
Nuclear Factor ◽  
Dna Binding Activity

The cellular response to DNA-damaging agents is partly mediated by DNA-binding transcription factors such as p53 and nuclear factor κB (NF-κB). Typically NF-κB activation is associated with resistance to apoptosis. Following stimulation with UV light however, NF-κB activation has been shown to be required for programmed cell death. To study this effect further and to determine the relationship between NF-κB and p53 function, we have examined the effect of UV light on U2OS cells. UV stimulation resulted in the activation of NF-κB DNA-binding and the induction of p53. Surprisingly, and in contrast with tumour necrosis factor α stimulation, this UV-induced NF-κB was transcriptionally inert. These observations suggest a model in which the NF-κB switch from an anti-apoptotic to a pro-apoptotic role within the cell results from modulation of its ability to stimulate gene expression, possibly as a result of the ability of p53 to sequester transcriptional co-activator proteins such as p300/CREB (cAMP-response-element-binding protein)-binding protein.

scholarly journals A novel DNA-binding motif in the nuclear matrix attachment DNA-binding protein SATB1

1994 ◽  
Vol 14 (3) ◽  
pp. 1852-1860
Author(s):  
K Nakagomi ◽  
Y Kohwi ◽  
L A Dickinson ◽  
T Kohwi-Shigematsu
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Direct Contact ◽  
Binding Protein ◽  
Binding Activity ◽  
Binding Domain ◽  
Binding Motif ◽  
Dna Binding Domain ◽  
Sequence Context ◽  
Dna Binding Activity

The nuclear matrix attachment DNA (MAR) binding protein SATB1 is a sequence context-specific binding protein that binds in the minor groove, making virtually no contact with the DNA bases. The SATB1 binding sites consist of a special AT-rich sequence context in which one strand is well-mixed A's, T's, and C's, excluding G's (ATC sequences), which is typically found in clusters within different MARs. To determine the extent of conservation of the SATB1 gene among different species, we cloned a mouse homolog of the human STAB1 cDNA from a cDNA expression library of the mouse thymus, the tissue in which this protein is predominantly expressed. This mouse cDNA encodes a 764-amino-acid protein with a 98% homology in amino acid sequence to the human SATB1 originally cloned from testis. To characterize the DNA binding domain of this novel class of protein, we used the mouse SATB1 cDNA and delineated a 150-amino-acid polypeptide as the binding domain. This region confers full DNA binding activity, recognizes the specific sequence context, and makes direct contact with DNA at the same nucleotides as the whole protein. This DNA binding domain contains a novel DNA binding motif: when no more than 21 amino acids at either the N- or C-terminal end of the binding domain are deleted, the majority of the DNA binding activity is lost. The concomitant presence of both terminal sequences is mandatory for binding. These two terminal regions consist of hydrophilic amino acids and share homologous sequences that are different from those of any known DNA binding motifs. We propose that the DNA binding region of SATB1 extends its two terminal regions toward DNA to make direct contact with DNA.

scholarly journals Redox Regulation of GA-binding Protein-α DNA Binding Activity

1996 ◽  
Vol 271 (41) ◽  
pp. 25617-25623 ◽  
Author(s):  
Mark E. Martin ◽  
Yurii Chinenov ◽  
Mi Yu ◽  
Tonya K. Schmidt ◽  
Xiu-Ying Yang
Keyword(s):  
Dna Binding ◽  
Redox Regulation ◽  
Binding Protein ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Ga Binding Protein

scholarly journals Inhibition of CCAAT/Enhancer Binding Protein Family DNA Binding in Mouse Epidermis Prevents and Regresses Papillomas

2007 ◽  
Vol 67 (4) ◽  
pp. 1867-1876 ◽  
Author(s):  
Won Jun Oh ◽  
Vikas Rishi ◽  
Andras Orosz ◽  
Michael J. Gerdes ◽  
Charles Vinson
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Protein Family ◽  
Mouse Epidermis ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein
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