K. Mitsunaganakatsubo et al., CDNA CLONING OF NA-ATPASE ALPHA-SUBUNIT FROM EMBRYOS OF THE SEA-URCHIN, HEMICENTROTUS-PULCHERRIMUS(,K+), Zoological science, 13(6), 1996, pp. 833-841
Na+, K+-ATPase alpha-subunit cDNA of the sea urchin, Hemicentrotus pul
cherrimus, was obtained by twice screening prism and gastrula lambda g
t10 cDNA libraries using an oligonucleotide probe derived from a mostl
y conserved region, FSBA (5'-p-(fluorosulfonyl)-benzoyladenosine) bind
ing site of cation transport ATPases. The 5'-end of the non-coding reg
ion was determined by primer extension and the region was amplified by
5'-RACE method. The sea urchin alpha-subunit cDNA consists of 4401 nu
cleotides and encodes 1038 amino acid residues (MW, 114 kDa). The pred
icted primary structure, except N-terminal region, has similar degree
of high homology to various metazoan Nac, K+-ATPase alpha-subunits. Al
ignment of amino acid sequence and a hydropathy profile also predicts
eight putative transmembrane segments at least. The phylogenetic tree
suspected from alignment of amino acid sequences of 21 species suggest
s that sea urchin and vertebrate Na+, K+-ATPase alpha-subunits seem to
have evolved from a common origin, before vertebrate alpha-subunit di
vided into three isoforms.