alexa Antagonism between apolipoprotein AI regulatory protein 1, Ear3 COUP-TF, and hepatocyte nuclear factor 4 modulates apolipoprotein CIII gene expression in liver and intestinal cells.


Biochemistry & Physiology: Open Access

Author(s): MietusSnyder M, Sladek FM, Ginsburg GS, Kuo CF, Ladias JA,

Abstract Share this page

Abstract Apolipoprotein CIII (apoCIII), a lipid-binding protein involved in the transport of triglycerides and cholesterol in the plasma, is synthesized primarily in the liver and the intestine. A cis-acting regulatory element, C3P, located at -90 to -66 upstream from the apoCIII gene transcriptional start site (+1), is necessary for maximal expression of the apoCIII gene in human hepatoma (HepG2) and intestinal carcinoma (Caco2) cells. This report shows that three members of the steroid receptor superfamily of transcription factors, hepatocyte nuclear factor 4 (HNF-4), apolipoprotein AI regulatory protein 1 (ARP-1), and Ear3/COUP-TF, act at the C3P site. HNF-4 activates apoCIII gene expression in HepG2 and Caco2 cells, while ARP-1 and Ear3/COUP-TF repress its expression in the same cells. HNF-4 activation is abolished by increasing amounts of ARP-1 or Ear3/COUP-TF, and repression by ARP-1 or Ear3/COUP-TF is alleviated by increasing amounts of HNF-4. HNF-4 and ARP-1 bind with similar affinities to the C3P site, suggesting that their opposing transcriptional effects may be mediated by direct competition for DNA binding. HNF-4 and ARP-1 mRNAs are present within the same cells in the liver and intestine, and protein extracts from hepatic tissue, HepG2, and Caco2 cells contain significantly more HNF-4 than ARP-1 or Ear3/COUP-TF binding activities. These findings suggest that the transcription of the apoCIII gene in vivo is dependent, at least in part, upon the intracellular balance of these positive and negative regulatory factors.
This article was published in Mol Cell Biol and referenced in Biochemistry & Physiology: Open Access

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 9th International Conference on Structural Biology
    September 18-20, 2017 Zurich, Switzerland

  •  2nd International Conference on Biochemistry
    Sep 21-22, 2017, Macau, Hong Kong
  • 2nd International Conference on Biochemistry
    September 28-29, 2017 Dubai, UAE

  • 3rd Annual Congress on Bioscience
    October 16-17, 2017 Dubai,UAE

  • 3rd International Conference on Transcriptomics
    October 30 - November 01, 2017 Bangkok, Thailand

  • 3rd International Conference on Genetic and Protein Engineering (10 Plenary Forums - 1 Event)
    November 08-09, 2017 Las Vegas, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version