NaSi-1 and Sat-1: structure, function and transcriptional regulation of two genes encoding renal proximal tubular sulfate transporters

Int J Biochem Cell Biol. 2005 Jul;37(7):1350-6. doi: 10.1016/j.biocel.2005.02.013.


Sulfate (SO(4)2-) is an important anion regulating many metabolic and cellular processes. Maintenance of SO4(2-) homeostasis occurs in the renal proximal tubule via membrane transport proteins. Two SO(4)2- transporters that have been characterized and implicated in regulating serum SO4(2-) levels are: NaSi-1, a Na+-SO(4)2- cotransporter located at the brush border membrane and Sat-1, a SO4(2-)-anion exchanger located on the basolateral membranes of proximal tubular cells. Unlike Sat-1, for which very few studies have looked at regulation of its expression, NaSi-1 has been shown to be regulated by various hormones and dietary conditions in vivo. To study this further, NaSi-1 (SLC13A1) and Sat-1 (SLC26A1) gene structures were determined and recent studies have characterized their respective gene promoters. This review presents the current understanding of the transcriptional regulation of NaSi-1 and Sat-1, and describes possible pathogenetic implications which arise as a consequence of altered SO(4)2- homeostasis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Anion Transport Proteins / genetics
  • Anion Transport Proteins / metabolism*
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / metabolism*
  • Humans
  • Kidney Tubules, Proximal / metabolism*
  • Promoter Regions, Genetic
  • Sodium Sulfate Cotransporter
  • Sulfates / metabolism*
  • Symporters / genetics
  • Symporters / metabolism*
  • Transcription, Genetic


  • Anion Transport Proteins
  • Cation Transport Proteins
  • Sodium Sulfate Cotransporter
  • Sulfates
  • Symporters