title: A functional mutation at position -155 in porcine APOE promoter affects gene expression.
abstract: BACKGROUND
  Apolipoprotein E, a component of the plasma lipoproteins, plays an important role in the transport and metabolism of cholesterol and other lipids. Three single nucleotide polymorphisms (SNPs) -491A>T, -219T>G and +113G>C in the regulatory region of human apolipoprotein E gene (APOE) change the promoter activity and are associated with a wide variety of disorders including Alzheimer disease (AD). Functional SNPs in porcine APOE gene 5' regulatory region have not been explored.
  
  
  RESULTS
  We examined SNPs within this region (from -831 to +855), and the analysis revealed that the T>A SNP at position -155 among these three polymorphism sites (-440, -155, +501) was found to exert a marked influence on the transcription of the porcine APOE gene. Electrophoretic mobility shift assays showed that the binding affinity of oligonucletides containing the -155A to transcription factor(s) was stronger than that of the -155T. Transient transfection assays and quantitative real-time PCR results revealed that the -155T>A variant enhanced the activity of the APOE promoter and was associated with increased APOE mRNA levels in vivo.
  
  
  CONCLUSIONS
  These data suggest that the -155T>A mutation in the promoter region of the porcine APOE gene is an important functional variant. The results provided new insights into aspects of pig genetics and might also facilitate the application of pigs in biomedical studies addressing important human diseases.
authors.affiliation: Guangdong Provincial Key Lab of Agroanimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, PR China.
authors.forename: Shixin
authors.initials: S
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.forename: Zanmou
authors.initials: Z
authors.lastname: Chen
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D034421:Sus scrofa / Q000235:genetics*
chemical_list: D001057:Apolipoproteins E; D012333:RNA, Messenger