Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/33811
Title: Sterol regulatory element binding protein-1a transactivates 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene promoter
Author: Metón Teijeiro, Isidoro
Egea, Míriam
Anemaet, Ida Guurtje
Fernández González, Felipe Javier
Vázquez Baanante, Ma. Isabel
Keywords: Orada
Enzims
Fetge
Metabolisme
Transcripció genètica
Sparus aurata
Enzymes
Liver
Metabolism
Genetic transcription
Issue Date: Jul-2006
Publisher: Association for the Study of Internal Secretions
Abstract: 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.
It is part of: Endocrinology, 2006, vol. 147, num. 7, p. 3446-3456
Related resource: http://dx.doi.org/10.1210/en.2005-1506
URI: http://hdl.handle.net/2445/33811
ISSN: 0013-7227
Appears in Collections:Articles publicats en revistes (Bioquímica i Biomedicina Molecular)
Articles publicats en revistes (Biologia Evolutiva, Ecologia i Ciències Ambientals)

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