This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Metón, I. Articles by Baanante, I. V. Search for Related Content PubMed PubMed Citation Articles by Metón, I. Articles by Baanante, I. V.

Sterol Regulatory Element Binding Protein-1a Transactivates 6-Phosphofructo-2-Kinase/Fructose-2,6-Bisphosphatase Gene Promoter

Departament de Bioquímica i Biologia Molecular (I.M., M.E., I.G.A., I.V.B.), Facultat de Farmàcia i Departament d’Ecologia (F.F.), Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain

Address all correspondence and requests for reprints to: I. V. Baanante, Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Diagonal 643, 08028 Barcelona, Spain. E-mail: baanantevazquez{at}ub.edu.

6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB) catalyzes the synthesis and degradation of fructose-2,6-bisphosphate, a key modulator of glycolysis-gluconeogenesis. To gain insight into the molecular mechanism behind hormonal and nutritional regulation of PFKFB expression, we have cloned and characterized the proximal promoter region of the liver isoform of PFKFB (PFKFB1) from gilthead sea bream (Sparus aurata). Transient transfection of HepG2 cells with deleted gene promoter constructs and electrophoretic mobility shift assays allowed us to identify a sterol regulatory element (SRE) to which SRE binding protein-1a (SREBP-1a) binds and transactivates PFKFB1 gene transcription. Mutating the SRE box abolished SREBP-1a binding and transactivation. The in vivo binding of SREBP-1a to the SRE box in the S. aurata PFKFB1 promoter was confirmed by chromatin immunoprecipitation assays. There is a great deal of evidence for a postprandial rise of PFKB1 mRNA levels in fish and rats. Consistently, starved-to-fed transition and treatment with glucose or insulin increased SREBP-1 immunodetectable levels, SREBP-1 association to PFKFB1 promoter, and PFKFB1 mRNA levels in the piscine liver. Our findings demonstrate involvement of SREBP-1a in the transcriptional activation of PFKFB1, and we conclude that SREBP-1a may exert a key role mediating postprandial activation of PFKFB1 transcription.

This article has been cited by other articles:

				X. Xie, H. Liao, H. Dang, W. Pang, Y. Guan, X. Wang, J. Y.-J. Shyy, Y. Zhu, and F. M. Sladek Down-Regulation of Hepatic HNF4{alpha} Gene Expression during Hyperinsulinemia via SREBPs Mol. Endocrinol., April 1, 2009; 23(4): 434 - 443. [Abstract] [Full Text] [PDF]

				P. Philip-Couderc, N. I. Tavares, A. Roatti, R. Lerch, C. Montessuit, and A. J. Baertschi Forkhead Transcription Factors Coordinate Expression of Myocardial KATP Channel Subunits and Energy Metabolism Circ. Res., February 1, 2008; 102(2): e20 - e35. [Abstract] [Full Text] [PDF]

				M Egea, I Meton, and I V Baanante Sp1 and Sp3 regulate glucokinase gene transcription in the liver of gilthead sea bream (Sparus aurata) J. Mol. Endocrinol., April 1, 2007; 38(4): 481 - 492. [Abstract] [Full Text] [PDF]