NaSi-1 and Sat-1: structure, function and transcriptional regulation of two genes encoding renal proximal tubular sulfate transporters.
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.
Lee
Aven
A
School of Biomedical Sciences, University of Queensland, Brisbane, Qld 4072, Australia.
Dawson
Paul A
PA
Markovich
Daniel
D
D000818:Animals; D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D000077003:Sodium Sulfate Cotransporter; D013431:Sulfates / Q000378:metabolism*; D027981:Symporters / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D027321:Anion Transport Proteins; D027682:Cation Transport Proteins; D000077003:Sodium Sulfate Cotransporter; D013431:Sulfates; D027981:Symporters