The yeast F1-ATPase beta subunit precursor contains functionally redundant mitochondrial protein import information.
The yeast F1-ATPase beta subunit precursor contains functionally redundant mitochondrial protein import information.
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酵母 F1-ATPase β 亚基前体含有功能冗余的线粒体蛋白输入信息。
DOI：
10.1128/mcb.7.11.4038-4047.1987
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发表时间：
1987
影响因子：
5.3
通讯作者：
Emr,SD
中科院分区：
文献类型：
--
作者：
Bedwell,DM;Klionsky,DJ;Emr,SD
酵母F1-ATP酶β亚基前体的NH 2末端指导该蛋白进入线粒体。为了确定该输入信号的功能重要组分，使用了寡核苷酸定向诱变将一系列缺失和错义突变引入到编码F1-β亚基前体的基因中。在这些突变中有三个非重叠缺失，两个在19个氨基酸的前序列内（Δ5-12和Δ16-19），一个在成熟蛋白内（Δ28-34）。含有这些缺失的不同组合的各种突变F1-β亚基蛋白的线粒体输入特性的表征表明，只有当所有三种缺失组合时，输入才被阻断。发现含有这些缺失的所有可能的单个和成对组合的突变蛋白保留了指导线粒体输入F1-β亚基的能力。这些数据表明F1-β亚基在其NH 2端含有冗余的输入信息。事实上，我们发现整个F1-β亚基前序列的缺失并不能阻止输入，这表明在成熟蛋白的NH 2末端附近存在功能性线粒体输入信号。此外，通过分析酵母中各种突变蛋白的线粒体输入，我们获得的证据表明，F1-β亚基输入信号的不同片段可能以相加或合作的方式发挥作用，以优化该蛋白的输入特性。
The NH2terminus of the yeast F1-ATPase β subunit precursor directs the import of this protein into mitochondria. To define the functionally important components of this import signal, oligonucleotide-directed mutagenesis was used to introduce a series of deletion and missense mutations into the gene encoding the F1-β subunit precursor. Among these mutations were three nonoverlapping deletions, two within the 19-amino-acid presequence (Δ5-12 and Δ16-19) and one within the mature protein (Δ28-34). Characterization of the mitochondrial import properties of various mutant F1-beta subunit proteins containing different combinations of these deletions showed that import was blocked only when all three deletions were combined. Mutant proteins containing all possible single and pairwise combinations of these deletions were found to retain the ability to direct mitochondrial import of the F1-β subunit. These data suggest that the F1-β subunit contains redundant import information at its NH2terminus. In fact, we found that deletion of the entire F1-β subunit presequence did not prevent import, indicating that a functional mitochondrial import signal is present near the NH2terminus of the mature protein. Furthermore, by analyzing mitochondrial import of the various mutant proteins in [rho-] yeast, we obtained evidence that different segments of the F1-β subunit import signal may act in an additive or cooperative manner to optimize the import properties of this protein.