Molecular mechanisms of protein sorting between the mitochondrial outer and inner membranes

线粒体外膜和内膜之间蛋白质分选的分子机制

基本信息

批准号：
63580151
负责人：
HASE Toshiharu
金额：
$ 1.28万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63580151/
关键词：
Mitochondria Membrane proteins Intracellular transport of proteins Cytochrome c_1 チトクロムc_1

项目摘要

Mitochondrial proteins synthesized in the cytoplasm are transported and localized to a specific compartment of the mitochondrion. The intramitochondrial sorting between the outer and inner membranes was investigated using a 70 kDa outer membrane protein and cytochrome c_1 as representative proteins in yeast cells. The presequence of cytochrome c_1, which functions as a signal to the inner membrane was replaced by various lengths of the N-terminal region of the 70 kDa protein. The fused protein with the N-terminal 61 residues(61mC_1) was localized to the outer membrane and those with less than 29 residues to the inner membrane. The latter fusion proteins were shown to be assembled into succinate-eytochrome c reductase without proteolytic removal of the fused region and restore the respiration of a cytochrome c_1 deficient mutant yeast(MH6-16). These date indicate that targeting and anchoring signals of the outer membrane protein localize the inner membrane protein to the outer membrane and that the target sequence alone directs it to the inner membrane.The cytochrome c_1 deficient mutant yeast, MH6-16 transformed with a plasmid encoding 61mC_1 was not able to grow on a non- fermentable medium(glycerol^-), due to location of this protein to the outer membrane. A selection for mutations which restored growth on glycerol was applied to the transformants and yield a class of invitation in the host genome. We are now characterizing this mutation as a mitochondrial protein sorting mutant and a DNA fragment involved in the restoration are currently isolated.

在细胞质中合成的线粒体蛋白被转运并定位于线粒体的特定区室。使用70 kDa的外膜蛋白和细胞色素C_1作为酵母细胞中的代表性蛋白，研究了外膜和内膜之间的膜软骨内分选。在70 kDa蛋白的N末端区域的各个长度代替了对内膜的信号的细胞色素C_1的presequence。与N末端61残基（61MC_1）的融合蛋白定位在外膜，而内膜少于29个残基。后一种融合蛋白被证明将其组装成琥珀酸盐 - 乳腺C还原酶，而无需蛋白水解去除融合区，并恢复细胞色素C_1缺陷型突变酵母（MH6-16）的呼吸。这些日期表明，外膜蛋白的靶向和锚定信号将内膜蛋白定位在外膜上，单独的靶序列将其引导到内膜内。细胞色素C_1缺陷型突变酵母MH6-16 MH6-16在质粒编码61MC_1上不可能在质量编码的位置（介导）介质 - 介于媒介中 - 到外膜。将恢复甘油生长的突变的选择应用于转化体，并在宿主基因组中产生一类邀请。现在，我们将这种突变表征为线粒体蛋白分选突变体，并且目前分离出参与恢复的DNA片段。