Phylogenetic conservation of isoform-specific regions within alpha-subunit of Na(+)-K(+)-ATPase

Abstract

Site-directed polyclonal antibodies were generated against four oligopeptides derived from the rat alpha-isoforms of Na(+)-K(+)-adenosinetriphosphatase (i.e., Na(+)-K+ pump) and were used to assess the phylogenetic conservation of the target regions. The first antibody was directed against a region near the phosphorylation site that is conserved among alpha-subunits from numerous species. The remaining antibodies were specific for the isoforms of alpha and recognized a region near the fluorescein isothiocyanate-reactive lysine of the adenine binding site. Immunoblots of protein from a number of species probed with these antibodies revealed dramatic differences in the conservation of the target sequences. The region derived from alpha 1 was found in four of the six mammals screened. In contrast, the analogous region derived from alpha 2 was found in all the screened mammals. Most conserved was the region derived from alpha 3, which was found in all the screened mammals as well as in chickens, catfish, dogfish, and sea slugs. Conservation of the region from alpha 3 suggests functional significance and implies that strong selective pressures have discouraged mutational change. Results from the immunoblots further suggest that isoforms are present in all vertebrates.

Modelling the effects of copper on soil organisms and processes using the free ion approach: Towards a multi-species toxicity model

“…Pressley, 1992;Ma et al, 2005). Further investigation of this 382 phenomenon would be facilitated with knowledge of  values for other organisms, 383 such as freshwater species.…”

Na + pump low and high ouabain affinity α subunit isoforms are differently distributed in cells

“…␣1 subunits were labeled with pAbs [either ''NASE'' (10) All antibodies used in this study have been well characterized (10,17,(21)(22)(23). Sample Western blots ( Fig.…”

“…The isoform-specific differences in the ouabain-binding region, especially in ␣2 and ␣3, are highly conserved in widely divergent species, but the physiological significance of these isoforms is not understood (4,10).…”

Distribution of the Na,K-ATPase α Subunit in the Rat Spiral Ganglion and Organ of Corti

“…Specificity of the antibodies for the NKAα1 has been verified by the vendor using Western blot analysis of rat brain microsomes (C464.6) and by Arystarkhova and Sweadner (1996) using Western blot analysis of membrane preparations from rat kidney, brainstem, and adult and neonatal heart (α6F). Specificity of the antibodies for the NKAα2 has been verified by Pressley (1992) using Western blot analysis of rat brain microsomes (anti-HERED) and by the vendor using immunohistochemistry to show membrane localization in rat retinal cells.…”