title: Nrf2 and Sp family synergistically enhance the expression of ion transporters in potassium-depleted conditions.
abstract: BACKGROUND
  During potassium (K) depletion, many adaptive responses are likely mediated through a complex network that involves expression of a variety of genes. We identified that the Nrf2 gene was differentially expressed between normal and K-depleted rat kidney.
  
  
  METHODS
  To investigate the effect of Nrf2 on colonic H/K-ATPase and kNBC1, overexpression of Nrf2 was carried out in 293T and CV1 cell lines, and experiments were conducted in low-K media. Sp family was cotransfected with Nrf2 to examine the relationship between the 2 molecules and their effect on ion transporters.
  
  
  RESULTS
  Ion transporters were activated by overexpression of Nrf2 and cotransfection of Nrf2 with Sp family genes showed additional enhancement of colonic H/K-ATPase and kNBC1 expression and their promoter activities. Pretreatment with low-K media increased the transcriptional activity of Nrf2, colonic H/K-ATPase and kNBC1. Furthermore, transfection of dominant-negative Nrf2 completely abolished low-K-mediated expression of the ion transporters.
  
  
  CONCLUSIONS
  These results suggest that Nrf2 mediates transcriptional activation of colonic H/K-ATPase and kNBC1 in response to K-depleted stress and augments Sp family-mediated expression of these ion transporters.
authors: Medical Research Center for Gene Regulation, Chonnam National University, Gwangju, Korea.
authors: Chang Bae
authors: CB
authors: Lee
authors: Yeon Sang
authors: YS
authors: Lee
authors: Ji Youn
authors: JY
authors: Lee
authors: Song Eun
authors: SE
authors: Lee
authors: Kyu Youn
authors: KY
authors: Ahn
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D017506:H(+)-K(+)-Exchanging ATPase / Q000235:genetics*; D006801:Humans; D017136:Ion Transport; D051267:NF-E2-Related Factor 2 / Q000502:physiology*; D011188:Potassium / Q000502:physiology*; D011401:Promoter Regions, Genetic; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D027982:Sodium-Bicarbonate Symporters / Q000235:genetics*; D051703:Sp Transcription Factors / Q000502:physiology*
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D017382:Reactive Oxygen Species; D027982:Sodium-Bicarbonate Symporters; D051703:Sp Transcription Factors; D017506:H(+)-K(+)-Exchanging ATPase; D011188:Potassium