Molecular cloning and characterization of cDNA encoding the GTP-binding protein alpha i and identification of a related protein, alpha h.
Molecular cloning and characterization of cDNA encoding the GTP-binding protein alpha i and identification of a related protein, alpha h.
复制标题
编码 GTP 结合蛋白 α i 的 cDNA 的分子克隆和表征以及相关蛋白 α h 的鉴定。
DOI：
10.1073/pnas.83.20.7663
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发表时间：
1986
影响因子：
11.1
通讯作者：
Neer,EJ
中科院分区：
文献类型：
--
作者：
Michel,T;Winslow,JW;Smith,JA;Seidman,JG;Neer,EJ
我们已经克隆并鉴定了编码GI的GTP结合亚基αI的cDNA，它是一种介导激素抑制腺苷酸环化酶和激素调节其他膜功能的蛋白质。我们还鉴定了一种编码一个推测的蛋白质的cDNA，我们将其命名为αh，它与αI高度同源，但不同于其他已知的GTP结合蛋白。这两个基因都是从牛脑下垂体文库中分离出来的。编码αI的两个胰酶多肽的氨基酸序列与由该基因推导的氨基酸序列完全一致，从而鉴定了编码αI的cDNA。我们还测定了从牛脑中提纯的一种相关的39 kDa蛋白质αo的多肽的氨基酸序列。这些序列与测定的αI序列大约75%相同。用放射性标记的αI、αh和相关蛋白质转导蛋白的α亚基作为探针，对牛基因组DNA进行的Southern杂交分析表明，每个探针识别不同的基因组DNA片段。我们的结果表明，G蛋白基因家族的组织具有更高水平的复杂性，具有非常相似结构特性的多个G蛋白可能被鉴定为不同基因的产物。
We have cloned and characterized cDNA encoding alpha i, the GTP-binding subunit of Gi, a protein that mediates hormonal inhibition of adenylate cyclase and hormonal regulation of other membrane functions. We have also identified cDNA encoding a putative protein, which we have named alpha h, that is highly homologous to alpha i but different from other known GTP-binding proteins. Both cDNAs were isolated from a bovine pituitary library. The cDNA encoding alpha i was identified by finding that the amino acid sequence determined for two tryptic peptides from alpha i agreed exactly with amino acid sequences deduced from the cDNA. We also determined the amino acid sequence of peptides derived from alpha o, a related 39-kDa protein purified from bovine brain. These sequences are approximately 75% identical to the sequence determined for alpha i. Southern blot analysis of bovine genomic DNA, using as probes radiolabeled cDNAs for alpha i, alpha h, and the alpha subunit of a related protein, transducin, showed that each probe recognized different genomic DNA fragments. Our results suggest a further level of complexity in the organization of the G-protein gene family, with multiple G proteins of very similar structural properties likely to be identified as products of distinct genes.