Primary structures of two types of alpha-subunit of rat brain Na+,K+,-ATPase deduced from cDNA sequences.
A rat brain cDNA library was screened by using as a probe a fragment of cDNA encoding the alpha-subunit of human Na+,K+-ATPase. Two different cDNA clones were obtained and analyzed. One of them was concluded to be a cDNA encoding the alpha-subunit of the weakly ouabain-sensitive rat kidney-type Na+,K+-ATPase. The deduced amino acid sequence consists of 1,018 amino acids. The alpha-subunit of the rat kidney-type Na+,K+-ATPase shows 97% homology in amino acid sequence with the alpha-subunit of human, sheep, or pig enzyme and 87% with that of Torpedo. Based on a comparison of the amino acid sequence at the extracellular domain of the alpha-subunit between weakly ouabain-sensitive rat kidney-type enzyme and the ouabain-sensitive human, sheep, pig, or Torpedo enzyme, it was proposed that only two significant amino acid replacements are unique to the rat kidney-type alpha-subunit. Another cDNA clone obtained showed 72% homology in nucleotide sequence with the former cDNA coding the alpha-subunit of the rat kidney-type Na+,K+-ATPase and the deduced amino acid sequence exhibited 85% homology with that of the alpha-subunit of rat kidney-type Na+,K+-ATPase.
Hara
Y
Y
Department of Biochemistry, Tokyo Medical and Dental University School of Medicine.
Urayama
O
O
Kawakami
K
K
Nojima
H
H
Nagamune
H
H
Kojima
T
T
Ohta
T
T
Nagano
K
K
Nakao
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000201:enzymology*; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D013045:Species Specificity
D046911:Macromolecular Substances; D004247:DNA; D000254:Sodium-Potassium-Exchanging ATPase