MOLECULAR-CLONING OF 3 DISTINCT FORMS OF THE NA+,K+-ATPASE ALPHA-SUBUNIT FROM RAT-BRAIN
MOLECULAR-CLONING OF 3 DISTINCT FORMS OF THE NA+,K+-ATPASE ALPHA-SUBUNIT FROM RAT-BRAIN
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DOI：
10.1021/bi00373a001
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发表时间：
1986-12-16
期刊：
影响因子：
2.9
通讯作者：
LINGREL, JB
中科院分区：
文献类型：
--
作者：
SHULL, GE;GREEB, J;LINGREL, JB
构建了大鼠脑和肾脏cDNA文库，并筛选了与绵羊肾脏Na+，K+-ATP酶催化亚基mRNA对应的cDNA插入片段。α-从肾文库中分离的亚基cDNA来源于一类信使RNA，而脑cDNA来源于三类信使RNA。最丰富的脑cDNA，跨越5.1个酶，编码α。（+）酶的形式。第二丰富的脑cDNA，跨越3.65个酶，与肾形式的相同，因此编码α。同种型第三类cDNA跨越3.55个内切酶，以低丰度存在，并编码α-内切酶的同种型。亚基，命名为α III，其先前未被鉴定。已测定了脑和肾cDNA的完整核苷酸序列和推导的氨基酸序列。此外，我们已经确定了一个富含赖氨酸的序列，可以作为一个可移动的，离子选择性的门在阳离子结合和闭塞，也确定了几个氨基酸序列的变化，似乎可以解释一些众所周知的物种和组织的差异，在心脏糖苷敏感性。
Rat brain and kidney cDNA libraries were constructed and screened with a cDNA insert corresponding to the mRNA for the sheep kidney Na+,K+-ATPase catalytic subunit. The .alpha.-subunit cDNAs isolated from the kidney library were derived from a single class of messenger RNA, and the brain cDNAs were derived from three classes of messenger RNA. The most abundant brain cDNA, which spans 5.1 kilobases, encodes the .alpha.(+) form of the enzyme. The second most abundant brain cDNA, which spans 3.65 kilobases, is identical with that of the kidney form and therefore encodes the .alpha. isoform. The third class of cDNA, which spans 3.55 kilobases, was present at low abundance and enodes an isoform of the .alpha.-subunit, designated, .alpha.III, which has not been identified previously. The complete nucleotide sequence and deduced amino acid sequence for each of the brain and kidney cDNAs have been determined. In addition, we have identified a lysine-rich sequence that may function as a movable, ion-selective gate during cation binding and occlusion and have also identified several amino acid sequence variations that appear to explain some of the well-known species and tissue differences in cardiac glucoside sensitivity.