Import of an incompletely folded precursor protein into isolated mitochondria requires an energized inner membrane, but no added ATP.
Import of an incompletely folded precursor protein into isolated mitochondria requires an energized inner membrane, but no added ATP.
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将不完全折叠的前体蛋白导入分离的线粒体需要通电的内膜，但不需要添加 ATP。
DOI：
10.1002/j.1460-2075.1987.tb02524.x
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Schatz,G
中科院分区：
文献类型：
--
作者：
Verner,K;Schatz,G
我们研究了不完整前体链翻译后导入分离的酵母线粒体。该前体是一种融合蛋白，含有一个连接到小鼠二氢叶酸还原酶的线粒体前序列。前体的体外合成被延长抑制剂放线菌酮中断，与核糖体共沉积的被捕获的新生链被EDTA释放。这些不完整的链被分离的酵母线粒体有效地导入;它们的导入类似于完整前体的导入，需要一个充满活力的内膜和线粒体前序列。它不同于完成的前体，在其耐甲氨蝶呤（仅结合正确折叠的二氢叶酸还原酶）和它的独立性添加ATP。不完整的链也比完整的前体对蛋白酶K更敏感。我们的结论是，不完整的链不完全折叠，并建议缺乏紧密折叠导致进口到线粒体成为独立的ATP。这意味着ATP可能直接或间接地参与前体的解折叠以将其运输到线粒体中。
We have studied the post‐translational import of incomplete precursor chains into isolated yeast mitochondria. The precursor was a fusion protein containing a mitochondrial presequence attached to mouse dihydrofolate reductase. In vitro‐synthesis of the precursor was interrupted by the elongation inhibitor cycloheximide and the arrested nascent chains cosedimenting with ribosomes were released by EDTA. These incomplete chains were efficiently imported by isolated yeast mitochondria; their import resembled that of the complete precursor in requiring an energized inner membrane and a mitochondrial presequence. It differed from that of the completed precursor in its resistance to methotrexate (which only binds to correctly folded dihydrofolate reductase) and its independence of added ATP. The incomplete chains were also more sensitive to proteinase K than the completed precursor. We conclude that the incomplete chains were incompletely folded and suggest that the lack of tight folding caused import into mitochondria to become independent of added ATP. This implies that ATP may participate, directly or indirectly, in the unfolding of the precursor for its transport into mitochondria.