Functional activity of oligosaccharide-deficient (Na,K)ATPase expressed in Xenopus oocytes.
(Na,K)ATPase from Torpedo californica was expressed in Xenopus laevis oocytes in the presence of tunicamycin by injecting mRNAs for the alpha- and beta-subunits derived from the cloned cDNAs into the oocytes. The oligosaccharide-deficient ATPase thus synthesized was transported to the oocyte plasma membrane, where it exhibited virtually the same ATPase activity, ouabain-binding capacity and 86Rb+ transport activity as the fully glycosylated enzyme. We conclude that the oligosaccharide chains on the beta-subunit has no effect on the catalytic activities of (Na,K)ATPase.
Takeda
K
K
Department of Biology, University of Occupational and Environmental Health, Kitakyushu, Japan.
Noguchi
S
S
Sugino
A
A
Kawamura
M
M
D000818:Animals; D005260:Female; D006023:Glycoproteins / Q000235:genetics; D007700:Kinetics; D009844:Oligosaccharides / Q000235:genetics*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics* / Q000378:metabolism; D014101:Torpedo; D014415:Tunicamycin / Q000494:pharmacology; D014982:Xenopus laevis
D006023:Glycoproteins; D009844:Oligosaccharides; D012333:RNA, Messenger; D014415:Tunicamycin; D000254:Sodium-Potassium-Exchanging ATPase