scholarly journals cAMP-response-element-binding-protein-binding protein (CBP) and p300 are transcriptional co-activators of early growth response factor-1 (Egr-1)

1998 ◽  
Vol 336 (1) ◽  
pp. 183-189 ◽  
Author(s):  
Eric S. SILVERMAN ◽  
Jing DU ◽  
Amy J. WILLIAMS ◽  
Raj WADGAONKAR ◽  
Jeffrey M. DRAZEN ◽  
...  

Egr-1 (early-growth response factor-1) is a sequence-specific transcription factor that plays a regulatory role in the expression of many genes important for cell growth, development and the pathogenesis of disease. The transcriptional co-activators CBP (cAMP-response-element-binding-protein-binding protein) and p300 interact with sequence-specific transcription factors as well as components of the basal transcription machinery to facilitate RNA polymerase II recruitment and transcriptional initiation. Here we demonstrate a unique way in which Egr-1 physically and functionally interacts with CBP/p300 to modulate gene transcription. CBP/p300 potentiated Egr-1 mediated expression of 5-lipoxygenase (5-LO) promoter–reporter constructs, and the degree of trans-activation was proportional to the number of Egr-1 consensus binding sites present in wild-type and naturally occurring mutants of the 5-LO promoter. The N- and C-terminal domains of CBP interact with the transcriptional activation domain of Egr-1, as demonstrated by a mammalian two-hybrid assay. Direct protein–protein interactions between CBP/p300 and Egr-1 were demonstrated by glutathione S-transferase fusion-protein binding and co-immunoprecipitation/Western-blot studies. These data suggest that CBP and p300 act as transcriptional co-activators for Egr-1-mediated gene expression and that variations between individuals in such co-activation could serve as a genetic basis for variability in gene expression.

2001 ◽  
Vol 20 (5) ◽  
pp. 590-594 ◽  
Author(s):  
Yuko Wada ◽  
Jun-ichi Suzuki ◽  
Motohiro Kawauchi ◽  
Masahiko Kurabayashi ◽  
Katsuaki Tsukioka ◽  
...  

2008 ◽  
Vol 99 (3) ◽  
pp. 481-486 ◽  
Author(s):  
Kazuki Mochizuki ◽  
Hiromi Kawai ◽  
Hiroko Mochizuki ◽  
Masaya Shimada ◽  
Sachiko Takase ◽  
...  

Fatty acids in milk are thought to play an important role in intestinal maturation and gene expression in the rat small intestine during the suckling–weaning period. In the present study, we determined the jejunal mRNA level of the cAMP-response-element-binding-protein-binding protein (CBP)/p300, which is one of the chromatin remodelling factors and regulates histone acetylation, during the postnatal period in rats. The mRNA level of CBP/p300 was high during the suckling and middle of the weaning period (day 5 to 20) and then declined sharply to a low level at the end of the weaning period and after weaning. In situ hybridisation also showed that CBP/p300 mRNA levels in the villus as well as the basal membrane clearly decreased after weaning. Rat pups at age 17 d, weaned to a high-fat diet, showed higher levels of CBP/p300 mRNA than those weaned to a low-fat diet. Oral administration of caprylic acid, oleic acid and linoleic acid, which are major fatty acid components in milk, induced jejunal CBP/p300 gene expression. The present results suggest that fatty acids in components of milk enhance expression of the CBP/p300 genes in the small intestine.


2005 ◽  
Vol 16 (7) ◽  
pp. 3365-3376 ◽  
Author(s):  
Ju-Ming Wang ◽  
Joseph T. Tseng ◽  
Wen-Chang Chang

The CCAAT/enhancer binding protein δ (C/EBPδ, CRP3, CELF, NF-IL6β) regulates gene expression and plays functional roles in many tissues, such as in acute phase response to inflammatory stimuli, adipocyte differentiation, and mammary epithelial cell growth control. In this study, we examined the expression of human C/EBPδ (NF-IL6β) gene by epidermal growth factor (EGF) stimulation in human epidermoid carcinoma A431 cells. NF-IL6β was an immediate-early gene activated by the EGF-induced signaling pathways in cells. By using 5′-serial deletion reporter analysis, we showed that the region comprising the –347 to +9 base pairs was required for EGF response of the NF-IL6β promoter. This region contains putative consensus binding sequences of Sp1 and cAMP response element-binding protein (CREB). The NF-IL6β promoter activity induced by EGF was abolished by mutating the sequence of cAMP response element or Sp1 sites in the –347/+9 base pairs region. Both in vitro and in vivo DNA binding assay revealed that the CREB binding activity was low in EGF-starved cells, whereas it was induced within 30 min after EGF treatment of A431 cells. However, no change in Sp1 binding activity was found by EGF treatment. Moreover, the phosphatidylinositol 3 (PI3)-kinase inhibitor (wortmannin) and p38MAPK inhibitor (SB203580) inhibited the EGF-induced CREB phosphorylation and the expression of NF-IL6β gene in cells. We also demonstrated that CREB was involved in regulating the NF-IL6β gene transcriptional activity mediated by p38MAPK. Our results suggested that PI3-kinase/p38MAPK/CREB pathway contributed to the EGF activation of NF-IL6β gene expression.


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