Ontogeny of renal sulfate transporters: postnatal mRNA and protein expression.
Renal reabsorption of inorganic sulfate changes during growth and development. We have studied the expression of two proximal tubular sulfate transporters, NaS(i)-1 and sat-1, during postnatal maturation. Both NaS(i)-1 and sat-1 mRNA levels increase postnatally, peaking at day 14, with a maximal tenfold increase in NaS(i)-1 and sat-1 mRNA levels compared with day 1. A similar age-dependent increase was observed for sodium-dependent and sodium-independent sulfate uptakes by injection of rat kidney mRNA into Xenopus oocytes. Western blot analysis of renal membranes from rats aged day 1 to day 77 showed no significant changes for NaS(i)-1 protein, whereas sat-1 protein levels paralleled mRNA expression, increasing from day 1 to day 14, followed by a decrease in protein levels thereafter. For NaSi-1 protein expression, translational or posttranslational mechanisms may maintain equal numbers of sulfate proteins on proximal tubular membranes during maturation, whereas sat-1 protein levels are in close agreement with mRNA changes. This is the first study to look at the ontogeny of renal sulfate transporter (NaS(i)-1 and sat-1) expression during postnatal maturation.
Markovich
D
D
Department of Physiology and Pharmacology, The University of Queensland, Brisbane, Queensland 4072, Australia. danielm@plpk.uq.edu.au
Fogelis
T S
TS
D000375:Aging; D000818:Animals; D001693:Biological Transport, Active; D015152:Blotting, Northern; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D026901:Membrane Transport Proteins; D012333:RNA, Messenger / Q000378:metabolism / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism*; D000076988:Sulfate Transporters; D013431:Sulfates / Q000378:metabolism*; D014982:Xenopus laevis
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D013431:Sulfates; D012964:Sodium