Molecular characterization of the human COQ5 C-methyltransferase in coenzyme Q10 biosynthesis.
Molecular characterization of the human COQ5 C-methyltransferase in coenzyme Q10 biosynthesis.
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DOI：
10.1016/j.bbalip.2014.08.007
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发表时间：
2014-11
期刊：
影响因子：
--
通讯作者：
Salviati L
中科院分区：
文献类型：
--
作者：
Nguyen TP;Casarin A;Desbats MA;Doimo M;Trevisson E;Santos-Ocaña C;Navas P;Clarke CF;Salviati L
Coq 5催化参与人类和酵母酿酒酵母中辅酶Q（Q或泛醌）生物合成的唯一C-甲基化。作为酵母中Q生产所需的十一种多肽之一，Coq 5也已被证明与称为CoQ-DNA组的多亚基复合物组装。在人类中，几个COQ基因的突变导致原发性Q缺乏，Q生物合成的减少与线粒体、心血管、肾脏和神经退行性疾病有关。在这项研究中，我们的特点，人辅酶Q5多肽和酵母辅酶Q5点和空突变体的互补研究。我们发现，人COQ 5 RNA在所有组织中表达，COQ 5多肽与基质侧的线粒体内膜相关。先前在酵母中的工作已经表明，保守的CoQ 5甲基转移酶基序内或附近的点突变导致Coq 5功能的丧失，但不是Coq 5稳态水平的丧失。在这里，我们表明，辅酶Q5点突变体内的辅酶Q8或辅酶Q5无效突变体中的过表达的辅酶Q8的稳定允许人辅酶Q5同系物部分恢复呼吸介质和Q6含量上的辅酶Q5突变体的生长。在分离的酵母线粒体中针对人Coq 5多肽的免疫印迹显示，人Coq 5多肽以与其他酵母Coq蛋白相同的高分子量在二维蓝色-天然/SDS-PAGE中迁移。结果表明，人和大肠杆菌辅酶Q5同源物在酵母中表达保留C-甲基转移酶活性，但能够拯救辅酶Q5酵母突变体只有当辅酶Q-tumorome组装。酵母Coq 5在辅酶Q生物合成中作为C-甲基转移酶发挥作用。人COQ 5位于人细胞的线粒体基质内。人辅酶Q5的表达部分拯救了酵母辅酶Q5点，但不是无效突变体。人COQ 5拯救酵母coq 5无效突变体，前提是Coq 8过表达。Coq 5同源物在辅酶Q-染色体组组装时拯救coq 5酵母突变体。
Coq5 catalyzes the only C-methylation involved in the biosynthesis of coenzyme Q (Q or ubiquinone) in humans and yeast Saccharomyces cerevisiae. As one of eleven polypeptides required for Q production in yeast, Coq5 has also been shown to assemble with the multi-subunit complex termed the CoQ-synthome. In humans, mutations in several COQ genes cause primary Q deficiency, and a decrease in Q biosynthesis is associated with mitochondrial, cardiovascular, kidney and neurodegenerative diseases. In this study, we characterize the human COQ5 polypeptide and examine its complementation of yeast coq5 point and null mutants. We show that human COQ5 RNA is expressed in all tissues and that the COQ5 polypeptide is associated with the mitochondrial inner membrane on the matrix side. Previous work in yeast has shown that point mutations within or adjacent to conserved COQ5 methyltransferase motifs result in a loss of Coq5 function but not Coq5 steady state levels. Here, we show that stabilization of the CoQ-synthome within coq5 point mutants or by over-expression of COQ8 in coq5 null mutants permits the human COQ5 homolog to partially restore coq5 mutant growth on respiratory media and Q6 content. Immunoblotting against the human COQ5 polypeptide in isolated yeast mitochondria shows that the human Coq5 polypeptide migrates in two-dimensional blue-native/SDS-PAGE at the same high molecular mass as other yeast Coq proteins. The results presented suggest that human and Escherichia coli Coq5 homologs expressed in yeast retain C-methyltransferase activity but are capable of rescuing the coq5 yeast mutants only when the CoQ-synthome is assembled. Yeast Coq5 functions as a C-methyltransferase in coenzyme Q biosynthesis. Human COQ5 is located within the mitochondria matrix of human cells. Expression of human COQ5 partially rescues yeast coq5 point but not null mutants. Human COQ5 rescues yeast coq5 null mutants provided that Coq8 is over-expressed. Coq5 homologs rescue the coq5 yeast mutants when the CoQ-synthome is assembled.
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DOI：
10.1016/j.bbalip.2013.12.017
发表时间：
2014-04-04
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
He CH;Xie LX;Allan CM;Tran UC;Clarke CF
通讯作者：
Clarke CF
影响因子：
4.8
作者：
Marbois, Beth;Xie, Letian X.;Clarke, Catherine F.
通讯作者：
Clarke, Catherine F.
影响因子：
3.9
作者：
Hsieh, Edward J.;Gin, Peter;Clarke, Catherine F.
通讯作者：
Clarke, Catherine F.
影响因子：
4.4
作者：
Chen, Shih-Wei;Liu, Chia-Chi;Yen, Hsiu-Chuan
通讯作者：
Yen, Hsiu-Chuan
影响因子：
8
作者：
Padilla, S.;Tran, U. C.;Jimenez-Hidalgo, M.;Lopez-Martin, J. M.;Martin-Montalvo, A.;Clarke, C. F.;Navas, P.;Santos-Ocana, C.
通讯作者：
Santos-Ocana, C.