title: The human pendrin promoter contains two N(4) GAS motifs with different functional relevance.
abstract: BACKGROUND
  Pendrin, an anion exchanger associated with the inner ear, thyroid and kidney, plays a significant role in respiratory tissues and diseases, where its expression is increased following IL-4 and IL-13 exposure. The mechanism leading to increased pendrin expression is in part due to binding of STAT6 to a consensus sequence (N4 GAS motif) located in the pendrin promoter. As retrospective analyses of the 5' upstream sequence of the human pendrin promoter revealed an additional N4 GAS motif (1660 base pairs upstream of the one previously identified), we set out to define its contribution to IL-4 stimulated changes in pendrin promoter activity.
  
  
  RESULTS
  Electrophoretic mobility shift assays showed that STAT6 bound to oligonucleotides corresponding to both N4 GAS motifs in vitro, while dual luciferase promoter assays revealed that only one of the N4 GAS motifs was necessary for IL-4 -stimulated increases in pendrin promoter activity in living cells. We then examined the ability of STAT6 to bind each of the N4 GAS motifs in vivo with a site-specific ChIP assay, the results of which showed that STAT6 interacted with only the N4 GAS motif that was functionally implicated in increasing the activity of the pendrin promoter following IL-4 treatment.
  
  
  CONCLUSIONS
  Of the two N4 GAS motifs located in the human pendrin promoter region analyzed in this study (nucleotides -3906 to +7), only the one located nearest to the first coding ATG participates in IL-4 stimulated increases in promoter activity.
authors.affiliation: Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Simone
authors.initials: S
authors.lastname: Vanoni
authors.forename: Charity
authors.initials: C
authors.lastname: Nofziger
authors.forename: Silvia
authors.initials: S
authors.lastname: Dossena
authors.forename: Selma M
authors.initials: SM
authors.lastname: Soyal
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Patsch
authors.forename: Paolo
authors.initials: P
authors.lastname: Plevani
authors.forename: Albert
authors.initials: A
authors.lastname: Duschl
authors.forename: Markus
authors.initials: M
authors.lastname: Paulmichl
mesh_terms: D001665:Binding Sites; D006801:Humans; D018793:Interleukin-13 / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D059372:Nucleotide Motifs / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D050800:STAT6 Transcription Factor / Q000737:chemistry / Q000235:genetics*; D000076988:Sulfate Transporters
chemical_list: C578095:IL13 protein, human; C508598:IL4 protein, human; D018793:Interleukin-13; D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D000076988:Sulfate Transporters; D015847:Interleukin-4