Localization of alpha-isoforms of Na(+)-K(+)-ATPase in rat kidney by in situ hybridization.
The expression of the three alpha-isoforms of Na(+)-K(+)-adenosine triphosphatase (ATPase) was examined in rat brain and rat kidney by Northern blot analysis. All three isoforms were detected in brain tissue while alpha 1-isoform was observed in whole kidney, suggesting that either this isoform was solely expressed in this organ or that alpha 2- and/or alpha 3-isoforms were not detected only because of their restricted distribution among a minority of specialized tubular cells. To distinguish between these two possibilities, in situ hybridization with rat alpha 1-, alpha 2-, and alpha 3-ATPase cRNA was performed on rat kidney sections. Results show that alpha 1-isoform expression largely predominates in the loop of Henle, distal tubule, and cortical collecting tubule. The labeling was drastically reduced by preincubation of sections with RNase. A sense cRNA probe, used as control, did not hybridize. With alpha 2- and alpha 3-probes, the labeling was low and uniformly distributed. In contrast, these two isoforms were clearly expressed in the brain, together with alpha 1. We conclude that only alpha 1-isoform of the Na(+)-K(+)-ATPase is detectable along the rat nephron. Its expression predominates in the tubular segments known to have a high Na(+)-K(+)-ATPase activity.
Farman
N
N
Département de Biologie, Centre d'Etudes Nucléaires de Saclay, Institut National de la Santé et de la Recherche Médicale U 246, Gif-sur-Yvette, France.
Corthesy-Theulaz
I
I
Bonvalet
J P
JP
Rossier
B C
BC
D000818:Animals; D016375:Antisense Elements (Genetics); D015152:Blotting, Northern; D001921:Brain / Q000201:enzymology; D004247:DNA / Q000032:analysis* / Q000235:genetics; D005260:Female; D007527:Isoenzymes / Q000235:genetics*; D007668:Kidney / Q000166:cytology / Q000201:enzymology*; D007672:Kidney Cortex / Q000201:enzymology; D007678:Kidney Glomerulus / Q000201:enzymology; D007679:Kidney Medulla / Q000201:enzymology; D007684:Kidney Tubules / Q000201:enzymology; D009693:Nucleic Acid Hybridization; D015347:RNA Probes; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*
D016375:Antisense Elements (Genetics); D007527:Isoenzymes; D015347:RNA Probes; D004247:DNA; D000254:Sodium-Potassium-Exchanging ATPase