Amino acid sequence of the alpha subunit of transducin deduced from the cDNA sequence.
Amino acid sequence of the alpha subunit of transducin deduced from the cDNA sequence.
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从 cDNA 序列推导的转导蛋白 α 亚基的氨基酸序列。
DOI：
10.1073/pnas.82.13.4311
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发表时间：
1985
影响因子：
11.1
通讯作者：
Bourne,HR
中科院分区：
文献类型：
--
作者：
Medynski,DC;Sullivan,K;Smith,D;VanDop,C;Chang,FH;Fung,BK;Seeburg,PH;Bourne,HR
转导蛋白是一种参与脊椎动物视网膜光转导的GTP结合蛋白，属于同源偶联蛋白家族，该家族还包括Gs和Gi，腺苷酸环化酶的调节蛋白。本文报道了转导素α亚基（T α）的cDNA序列和推导的氨基酸序列。通过用抗体探针筛选，从表达载体λ gt 11中的牛视网膜cDNA文库中分离cDNA。2.2-腺苷酸酶cDNA插入片段与牛视网膜提取物中存在的单一2.6-腺苷酸酶poly（A）+ RNA种类杂交，但不与牛心脏、肝脏或脑的提取物杂交。cDNA的核苷酸序列揭示了一个足够长的开放阅读框架，以编码整个39-kDa的T α多肽。从cDNA推导的多肽序列将由350个氨基酸组成，分子量为39，971。部分序列与报道的T α胰蛋白酶片段的氨基酸序列相匹配，包括霍乱和百日咳毒素特异性ADP核糖基化的位点。预测的序列还包括四个片段，长度范围从11至19个残基，表现出显着的同源性的GTP结合蛋白，包括人和酵母的ras蛋白和细菌中的核糖体蛋白合成的延伸因子，EF-G和EF-Tu的序列。结合以前的功能研究的胰蛋白酶片段的T α，推导的氨基酸序列使得有可能预测哪些部分的多肽与其他分子参与视网膜光转导。
Transducin, a GTP-binding protein involved in phototransduction in the vertebrate retina, belongs to a family of homologous coupling proteins that also includes Gs and Gi, the regulatory proteins of adenylate cyclase. Here we report the cDNA sequence and deduced amino acid sequence of transducin's alpha subunit (T alpha). The cDNA was isolated, by screening with an antibody probe, from a bovine retinal cDNA library in the expression vector lambda gt11. The 2.2-kilobase cDNA insert hybridized to a single 2.6-kilobase poly(A)+ RNA species present in extracts of bovine retina but not of bovine heart, liver, or brain. The nucleotide sequence of the cDNA revealed an open reading frame long enough to encode the entire 39-kDa T alpha polypeptide. The polypeptide sequence deduced from the cDNA would be composed of 350 amino acids and have a molecular weight of 39,971. Portions of the sequence matched reported amino acid sequences of T alpha tryptic fragments, including sites specifically ADP-ribosylated by cholera and pertussis toxins. The predicted sequence also includes four segments, ranging from 11 to 19 residues in length, that exhibit significant homology to sequences of GTP-binding proteins, including the ras proteins of man and yeast and the elongation factors of ribosomal protein synthesis in bacteria, EF-G and EF-Tu. In combination with previous functional studies of tryptic fragments of T alpha, the deduced amino acid sequence makes it possible to predict which portions of the polypeptide interact with other molecules involved in retinal phototransduction.