Membrane protein degradation by AAA proteases in mitochondria: Extraction of substrates from either membrane surface
Membrane protein degradation by AAA proteases in mitochondria: Extraction of substrates from either membrane surface
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DOI：
10.1016/s1097-2765(00)80242-7
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发表时间：
2000-04-01
期刊：
影响因子：
16
通讯作者：
Langer, T
中科院分区：
文献类型：
--
作者：
Leonhard, K;Guiard, B;Langer, T
两个AAA蛋白酶，其催化位点在相对的膜表面，介导线粒体内膜蛋白的ATP依赖性降解。我们在这里证明，在膜的两侧含有亲水结构域的模型底物多肽可以完全降解的AAA蛋白酶，如果溶剂暴露的结构域是在展开状态。从膜表面突出的短蛋白质尾足以允许AAA蛋白酶的蛋白水解攻击，其促进在相对侧的结构域解折叠。我们的研究结果提供了一个理由AAA蛋白酶在线粒体中的膜安排，并表明膜蛋白降解的AAA蛋白酶涉及跨膜段的主动提取和跨膜的溶剂暴露域的运输。
Two AAA proteases, each with its catalytic site at the opposite membrane surface, mediate the ATP-dependent degradation of mitochondrial inner membrane proteins. We demonstrate here that a model substrate polypeptide containing hydrophilic domains at both sides of the membrane can be completely degraded by either of the AAA proteases, if solvent-exposed domains are in an unfolded state. A short protein tail protruding from the membrane surface is sufficient to allow the proteolytic attack of an AAA protease that facilitates domain unfolding at the opposite side. Our results provide a rationale for the membrane arrangement of AAA proteases in mitochondria and demonstrate that degradation of membrane proteins by AAA proteases involves an active extraction of transmembrane segments and transport of solvent-exposed domains across the membrane.