Expression of hybrid (Na+ + K+)-ATPase molecules after transfection of mouse Ltk-cells with DNA encoding the beta-subunit of an avian brain sodium pump
In: Journal of Biological Chemistry, Jg. 262 (1987-08-01), S. 10733-10740
Online
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Zugriff:
A cDNA encoding the beta-subunit of the (Na+ + K+)-ATPase was cloned from a chicken brain cDNA library, and its nucleotide sequence was determined. High cross-species sequence homologies were found both in coding and noncoding regions. The cDNA was subcloned into a shuttle vector derived from pSV2CAT and was stably incorporated into mouse Ltk-cells. The avian beta-subunit was expressed on the cell surface (1-8 X 10(5) molecules/cell) complexed with alpha-subunits of the murine (Na+ + K+)-ATPase. In the hybrid system there was rapid assembly of subunits, post-translational N-glycosylations of the beta-subunit at its three Asn-X-Ser (or Thr) positions, and modification of high mannose oligosaccharides to complex type. Avian beta-subunits expressed in the mouse cells had an apparent molecular weight of about 55,000 as compared with 47,000 in avian cells, due to post-translational modifications, presumably differences in complex oligosaccharides. Despite the high number of interspecies hybrid (Na+ + K+)-ATPase molecules, the cells had none of the high affinity ouabain binding sites (KD = 2 X 10(-7) M) characteristic of avian cells, consistent with the view that the ouabain binding site is located largely or exclusively on the alpha-subunit and is not greatly affected by alpha-beta interaction.
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Expression of hybrid (Na+ + K+)-ATPase molecules after transfection of mouse Ltk-cells with DNA encoding the beta-subunit of an avian brain sodium pump
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Autor/in / Beteiligte Person: | Takeyasu, K ; Fambrough, Douglas M. ; Tamkun, Michael M. ; N R Siegel |
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Zeitschrift: | Journal of Biological Chemistry, Jg. 262 (1987-08-01), S. 10733-10740 |
Veröffentlichung: | Elsevier BV, 1987 |
Medientyp: | unknown |
ISSN: | 0021-9258 (print) |
DOI: | 10.1016/s0021-9258(18)61025-7 |
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