The Influence of Nuclear Factors in Hybrid Development Studied by Transplantation

1937 ◽  
Vol 71 (733) ◽  
pp. 127-142 ◽  
Author(s):  
Victor C. Twitty
2005 ◽  
Vol 19 (9) ◽  
pp. 2320-2334 ◽  
Author(s):  
Amena Archer ◽  
Dominique Sauvaget ◽  
Valérie Chauffeton ◽  
Pierre-Etienne Bouchet ◽  
Jean Chambaz ◽  
...  

Abstract In the small intestine, the expression of the apolipoprotein (apo) C-III and A-IV genes is restricted to the enterocytes of the villi. We have previously shown that, in transgenic mice, specific expression of the human apo C-III requires a hormone-responsive element (HRE) located in the distal region of the human apoA-IV promoter. This HRE binds the hepatic nuclear factors (HNF)-4α and γ. Here, intraduodenal injections in mice and infections of human enterocytic Caco-2/TC7 cells with an adenovirus expressing a dominant-negative form of HNF-4α repress the expression of the apoA-IV gene, demonstrating that HNF-4 controls the apoA-IV gene expression in enterocytes. We show that HNF-4α and γ functionally interact with a second HRE present in the proximal region of the human apoA-IV promoter. New sets of transgenic mice expressing mutated forms of the promoter, combined with the human apo C-III enhancer, demonstrate that, whereas a single HRE is sufficient to reproduce the physiological cephalo-caudal gradient of apoA-IV gene expression, both HREs are required for expression that is restricted to villi. The combination of multiple HREs may specifically recruit regulatory complexes associating HNF-4 and either coactivators in villi or corepressors in crypts.


FEBS Letters ◽  
1999 ◽  
Vol 459 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Bee Yen Teo ◽  
Nguan Soon Tan ◽  
Toong Jin Lam ◽  
Jeak Ling Ding

1990 ◽  
Vol 10 (7) ◽  
pp. 3357-3364 ◽  
Author(s):  
P G Quinn ◽  
D K Granner

We have examined the binding of factors in rat liver nuclear extracts to the phosphoenolpyruvate carboxykinase (PEPCK) gene cyclic AMP (cAMP) response element (CRE) and other CREs and have isolated a rat liver CRE-binding protein (CREBP) cDNA. In addition, we have examined the influence of altering the phosphorylation state of nuclear factors on both CRE binding and in vitro transcription. Specific binding to the PEPCK CRE was measured in a mobility shift assay. CRE sequences of the PEPCK, somatostatin, and glycoprotein hormone alpha subunit genes competed equally for binding of rat liver nuclear factors to the PEPCK CRE, whereas mutant PEPCK CRE sequences did not compete for binding. Oligonucleotides complementary to rat pheochromocytoma CREBP (Gonzalez et al., Nature [London] 337:749-752, 1989) were used to prime rat liver and brain cDNA in the polymerase chain reaction. The predominant CREBP molecule obtained was identical to the rat pheochromocytoma CREBP except for a 14-amino-acid deletion in the N-terminal half that was also present in a human placental cDNA (Hoeffler et al., Science 242:1430-1433, 1988). The regulation of transcription by cAMP was examined by coincubation of rat liver nuclear extract with the purified catalytic subunit of cAMP-dependent protein kinase (protein kinase A). Although binding to the CRE was unaffected, in vitro transcription directed by the PEPCK promoter was stimulated by catalytic subunit, and this effect was blocked by protein kinase inhibitor peptide. In contrast, when nuclear extract was coincubated with phosphatase, there was substantial inhibition of in vitro transcription directed by the PEPCK promoter, but there was no effect on binding to the CRE. The major effects of catalytic subunit were exerted through the CRE, but residual stimulation was evident in promoter fragments containing only the TATA element. These data suggest that factors are bound to the CRE at constitutively high levels and that their capacity for transcriptional activation is regulated by phosphorylation.


1990 ◽  
Vol 10 (5) ◽  
pp. 2418-2422 ◽  
Author(s):  
M Trus ◽  
N Benvenisty ◽  
H Cohen ◽  
L Reshef

A sequential pattern of interactions of trans-acting factors in rat liver with the phosphoenolpyruvate carboxykinase promoter during late development was observed. A liver-enriched factor, possibly AF1, interacted with the promoter in fetal liver, whereas a factor with the characteristics of C/EBP bound the promoter after birth with the onset of the gene expression.


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