Ouabain-sensitive H,K-ATPase: tissue-specific expression of the mammalian genes encoding the catalytic alpha subunit

Human ATP1AL1 and corresponding genes of other mammals encode the catalytic alpha submit of a non-gastric ouabain-sensitive H,K-ATPases, the ion pump presumably involved in maintenance of potassium homeostasis. The tissue spe cificity of the expression of these genes in different species has not been analyzed in detail. Here we report comparative RTPCR screening of mouse, r at, rabbit, human, and dog tissues. Significant expression levels were obse rved in the skin, kidney and distal colon of all species (with the exceptio n of the human colon). Analysis of rat urogenital organs also revealed stro ng expression in coagulating and preputial glands. Relatively lower express ion levels were detected in many other tissues including brain, placenta an d lung. In rabbit brain the expression was found to be specific to choroid plexus and cortex, Prominent similarity of tissue-specific expression patte rns indicates that animal and human non-gastric N,K-ATPases are indeed prod ucts of homologous genes. This is also consistent with the high sequence si milarity of non-gastric PI,K-ATPases (including partial sequences of hither to unknown cDNAs for mouse and dog proteins). (C) 1998 Federation of Europe an Biochemical Societies.