Saccharomyces cerevisiae Coq9 polypeptide is a subunit of the mitochondrial coenzyme Q biosynthetic complex
Saccharomyces cerevisiae Coq9 polypeptide is a subunit of the mitochondrial coenzyme Q biosynthetic complex
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DOI：
10.1016/j.abb.2007.02.016
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发表时间：
2007-07-01
影响因子：
3.9
通讯作者：
Clarke, Catherine F.
中科院分区：
文献类型：
--
作者：
Hsieh, Edward J.;Gin, Peter;Clarke, Catherine F.
辅酶Q(Q是一种氧化还原活性脂质，是电子传递链的重要组成部分。在这里，我们证明了酵母线粒体中Coq3、Coq4、Coq6、Coq7和Coq9多肽的稳定水平取决于其他Coq基因的表达。亚线粒体亚定位研究表明，Coq9p是一种位于线粒体内膜基质侧的外周膜蛋白。为了研究Coq9p是否是Q生物合成蛋白复合体的组成部分，用Blue Native-PAGE测定了Coq9p的天然分子质量。Coq9p与Coq3p和Coq4p共迁移，分子质量约为1 mda。HA标记的Coq9多肽与Coq4p、Coq5p、Coq6p和Coq7p之间存在直接的物理相互作用。这些发现与其他鉴定Coq3p和Coq4p相互作用的工作一起，在一个多亚基Q生物合成复合体中至少鉴定了六个Coq多肽。(C)2007 Elsevier Inc.保留所有权利。
Coenzyme Q (Q is a redox active lipid that is an essential component of the electron transport chain. Here, we show that steady state levels of Coq3, Coq4, Coq6, Coq7 and Coq9 polypeptides in yeast mitochondria are dependent on the expression of each of the other COQ genes. Submitochondrial localization studies indicate Coq9p is a peripheral membrane protein on the matrix side of the mitochondrial inner membrane. To investigate whether Coq9p is a component of a complex of Q-biosynthetic proteins, the native molecular mass of Coq9p was determined by Blue Native-PAGE. Coq9p was found to co-migrate with Coq3p and Coq4p at a molecular mass of approximately 1 MDa. A direct physical interaction was shown by the immunoprecipitation of HA-tagged Coq9 polypeptide with Coq4p, Coq5p, Coq6p and Coq7p. These findings, together with other work identifying Coq3p and Coq4p interactions, identify at least six Coq polypeptides in a multi-subunit Q biosynthetic complex. (c) 2007 Elsevier Inc. All rights reserved.