In vitro synthesis and posttranslational uptake of cytochrome c into isolated mitochondria: role of a specific addressing signal in the apocytochrome.
In vitro synthesis and posttranslational uptake of cytochrome c into isolated mitochondria: role of a specific addressing signal in the apocytochrome.
复制标题
细胞色素 c 的体外合成和翻译后摄取到分离的线粒体中：脱辅基细胞色素中特定寻址信号的作用。
DOI：
10.1073/pnas.78.7.4368
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发表时间：
1981
影响因子：
11.1
通讯作者：
Morimoto,T
中科院分区：
文献类型：
--
作者：
Matsuura,S;Arpin,M;Hannum,C;Margoliash,E;Sabatini,DD;Morimoto,T
向大鼠给予甲状腺激素3，3，5 '-三碘-L-甲状腺原氨酸（T3）导致细胞色素c的肝脏mRNA水平显著增加。从T3处理的大鼠的游离多核糖体制备的信使RNA指导了多肽的体外合成，该多肽仅在氨基酸序列上与成熟细胞色素c不同，因为它含有NH 2-末端甲硫氨酸。体外产物被特异性地掺入纯化的大鼠肝线粒体中，并且当翻译完成后加入线粒体时，加入的胰蛋白酶无法接近。马心脱辅基细胞色素c，但不是全细胞色素，可以竞争在体外合成的多肽，其摄取到线粒体。这表明作为线粒体寻址信号的脱辅基细胞色素c的主要结构特征在血红素获得后被掩蔽，并且该过程发生在线粒体中。寻址信号似乎包含在细胞色素多肽的特定片段中，因为只有一个由马脱辅基细胞色素c的CNBr切割产生的片段（从残基66延伸到分子的羧基末端）可以与体外产物竞争转移到线粒体中。
Administration of the thyroid hormone 3,3,5'-triiodo-L-thyronine (T3) to rats leads to a marked increase in hepatic levels of mRNA for cytochrome c. Messenger RNA prepared from the free polysomes of T3-treated rats directed the in vitro synthesis of a polypeptide which only differed in amino acid sequence from mature cytochrome c in that it contained an NH2-terminal methionine. The in vitro product was incorporated specifically into purified rat liver mitochondria and became inaccessible to added trypsin when the mitochondria were added after translation was completed. Horse heart apocytochrome c, but not the holocytochrome, could compete with the in vitro synthesized polypeptide for its uptake into mitochondria. This suggests that the primary structural features of apocytochrome c, which serve as an addressing signal for mitochondria, are masked after the acquisition of heme and that this process occurs in the mitochondria. The addressing signal seems to be contained in a specific segment of the cytochrome polypeptide because only one fragment generated by CNBr cleavage of horse apocytochrome c, extending from residue 66 to the carboxy end of the molecule, could compete with the in vitro product for its transfer into mitochondria.