PROTEIN IMPORT INTO YEAST MITOCHONDRIA IS ACCELERATED BY THE OUTER-MEMBRANE PROTEIN MAS70
PROTEIN IMPORT INTO YEAST MITOCHONDRIA IS ACCELERATED BY THE OUTER-MEMBRANE PROTEIN MAS70
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DOI：
10.1002/j.1460-2075.1990.tb07517.x
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发表时间：
1990-10-01
期刊：
影响因子：
11.4
通讯作者：
SCHATZ, G
中科院分区：
文献类型：
--
作者：
HINES, V;BRANDT, A;SCHATZ, G
酵母线粒体外膜含有主要的 70 kd 蛋白质，具有氨基末端疏水性膜锚和暴露于胞质溶胶的亲水性 60 kd 结构域。我们现在表明，这种蛋白质（我们称之为 MAS70）可加速许多（但不是全部）前体蛋白质的线粒体输入。抗MAS70 IgG或通过温和的胰蛋白酶处理或通过破坏核MAS70基因从线粒体去除MAS70抑制F1-ATP酶β-亚基、ADP/ATP转位子和几种其他前体向分离的线粒体的输入高达75%，但对孔蛋白的输入几乎没有影响。 mas70无效突变体的完整细胞导入F1-ATP酶α亚基和β亚基、细胞色素c1和其他前体的速度至少比野生型细胞慢几倍。从野生型线粒体中去除 MAS70 会抑制 ADP/ATP 转位子与线粒体表面的结合，表明 MAS70 介导最早的输入步骤之一。因此，几种前体通过 MAS70 作为受体样成分的途径输入。 MAS70 对于进口这些前体并不是必需的，但只会加速这一过程。
The yeast mitochondrial outer membrane contains a major 70 kd protein with an amino-terminal hydrophobic membrane anchor and a hydrophilic 60 kd domain exposed to the cytosol. We now show that this protein (which we term MAS70) accelerates the mitochondrial import of many (but not all) precursor proteins. Anti-MAS70 IgGs or removal of MAS70 from the mitochondria by either mild trypsin treatment or by disrupting the nuclear MAS70 gene inhibits import of the F1-ATPase .beta.-subunit, the ADP/ATP translocator, and of several other precursors into isolated mitochondria by up to 75%, but has little effect on the import of porin. Intact cells of a mas70 null mutant import the F1-ATPase .alpha.-subunit and .beta.-subunits, cytochrome c1 and other precursors at least several fold more slowly than wild-type cells. Removal of MAS70 from wild-type mitochondria inhibits binding of the ADP/ATP translocator to the mitochondrial surface, indicating that MAS70 mediates one of the earliest import steps. Several precursors are thus imported by a pathway in which MAS70 functions as a receptor-like component. MAS70 is not essential for import of these precursors, but only accelerates this process.