Physiol. Genomics 34: 144-148, 2008.
First published May 13, 2008; doi:10.1152/physiolgenomics.00043.2008
1094-8341/08 $8.00
Received 27 February 2008;
accepted in final form 7 May 2008.
Physiological Genomics 34:144-148 (2008)
1094-8341/08 $8.00 © 2008 American Physiological Society
The g.763G>C SNP of the bovine FASN gene affects its promoter activity via Sp-mediated regulation: implications for the bovine lactating mammary gland
Laura Ordovás1,
Rosa Roy2,
Sandra Pampín3,
Pilar Zaragoza1,
Rosario Osta1,
Jose Carlos Rodríguez-Rey3 and
Clementina Rodellar1
1 Laboratorio de Genética Bioquímica (LAGENBIO), Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza
2 Unidad de Genética, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid
3 Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
Fatty acid synthase (FASN) is an enzyme that catalyzes de novo synthesis of fatty acids in cells. The bovine FASN gene maps to BTA 19, where several quantitative trait loci for fat-related traits have been described. Our group recently reported the identification of a single nucleotide polymorphism (SNP), g.763G>C, in the bovine FASN 5' flanking region that was significantly associated with milk fat content in dairy cattle. The g.763G>C SNP was part of a GC-rich region that may constitute a cis element for members of the Sp transcription factor family. Thus the SNP could alter the transcription factor binding ability of the FASN promoter and consequently affect the promoter activity of the gene. However, the functional consequences of the SNP on FASN gene expression are unknown. The present study was therefore directed at elucidating the underlying molecular mechanism that could explain the association of the SNP with milk fat content. Three cellular lines (3T3L1, HepG2, and MCF-7) were used to test the promoter and the transcription factor binding activities by luciferase reporter assays and electrophoretic mobility shift assays, respectively. Band shift assays were also carried out with nuclear extracts from lactating mammary gland (LMG) to further investigate the role of the SNP in this tissue. Our results demonstrate that the SNP alters the bovine FASN promoter activity in vitro and the Sp1/Sp3 binding ability of the sequence. In bovine LMG, the specific binding of Sp3 may account for the association with milk fat content.
fatty acid synthase; Sp1; Sp3; transcription factor binding activity
Copyright © 2008 by the American Physiological Society.