Kuno T, Takeda T, Hirai M, Ito A, Mukai H, Tanaka C
Department of Pharmacology, Kobe University School of Medicine, Japan.
Biochem Biophys Res Commun. 1989 Dec 29;165(3):1352-8. doi: 10.1016/0006-291x(89)92752-6.
We have used a previously characterized rat cDNA clone for the catalytic (A) subunit of calmodulin-dependent protein phosphatase (calcineurin), which we designated A alpha, to isolate cDNA clones coding for a second isoform of the A subunit, A beta. The A beta cDNA encodes a protein of 525 amino acids that is 81% identical with A alpha. The N-terminal region is dissimilar and contains a characteristic proline-rich sequence. The region homologous to protein phosphatases 1 and 2A (region between residues 87 and 338, 91% identical) and the calmodulin binding domain (region between residues 401 and 424, 96% identical) are highly conserved. The presence of two genes coding for calcineurin A suggests the possibility of important functional differences in the two enzymes.
我们使用了一个先前已鉴定的大鼠cDNA克隆，该克隆编码钙调蛋白依赖性蛋白磷酸酶（钙神经素）的催化（A）亚基，我们将其命名为Aα，以分离编码A亚基第二种同工型Aβ的cDNA克隆。Aβ cDNA编码一个由525个氨基酸组成的蛋白质，该蛋白质与Aα的同源性为81%。其N端区域不同，含有一个特征性的富含脯氨酸的序列。与蛋白磷酸酶1和2A同源的区域（87至338位残基之间的区域，同源性为91%）以及钙调蛋白结合结构域（401至424位残基之间的区域，同源性为96%）高度保守。存在两个编码钙神经素A的基因，这表明这两种酶可能存在重要的功能差异。
