Expression of active alpha-3 subunit of rat brain Na+,K+-ATPase from the messenger RNA injected into Xenopus oocytes.
Cloned cDNA encoding the so-far uncharacterized alpha-3 subunit of rat brain Na+,K+-ATPase (Hara et al. (1987) J. Biochem. 102, 43-58, Shull et al. (1986) Biochemistry 25, 8125-8132) was incorporated into a vector carrying the SP6 promoter. The mRNA produced in vitro was injected into Xenopus oocytes with the mRNA encoding the Na+,K+-ATPase beta subunit of Torpedo electroplax. Increased Na+,K+-ATPase activity in the oocyte membrane was observed. This newly expressed activity was inhibited by ouabain (Ki = 1.5 x 10(-7) M), suggesting that the alpha-3 subunit of rat brain Na+,K+-ATPase is a highly ouabain-sensitive catalytic subunit.
Hara
Y
Y
Dept. of Biochemistry, Tokyo Medical and Dental University School of Medicine, Japan.
Ohtsubo
M
M
Kojima
T
T
Noguchi
S
S
Nakao
M
M
Kawamura
M
M
D000818:Animals; D001921:Brain / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology; D009865:Oocytes; D010042:Ouabain / Q000494:pharmacology; D012333:RNA, Messenger / Q000008:administration & dosage; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000235:genetics*; D013329:Structure-Activity Relationship; D014162:Transfection; D014981:Xenopus
D012333:RNA, Messenger; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase