Change of subunit composition of mitochondrial complex II (succinate-ubiquinone reductase/quinol-fumarate reductase) in Ascaris suum during the migration in the experimental host
Change of subunit composition of mitochondrial complex II (succinate-ubiquinone reductase/quinol-fumarate reductase) in Ascaris suum during the migration in the experimental host
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DOI：
10.1016/j.parint.2007.08.002
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发表时间：
2008-03-01
影响因子：
1.9
通讯作者：
Kita, Kiyoshi
中科院分区：
文献类型：
--
作者：
Iwata, Fumiko;Shinjyo, Noniko;Kita, Kiyoshi
猪蛔虫（Ascaris suum）的线粒体代谢途径在其生活史中发生了巨大的变化，以适应环境氧浓度的变化。我们以前证明了A.猪线粒体表达复合物II阶段特异性同种型（琥珀酸-泛醌还原酶：SQR/喹啉-延胡索酸还原酶：QFR）。成虫复合体II中的黄素蛋白（Fp）和细胞色素B小亚基（CybS）不同于感染性第三期幼虫（L3）复合体II。然而，在铁硫簇（Ip）或细胞色素B大亚基（CybL）之间的成人和复合物II的L3亚型没有差异。本研究旨在阐明呼吸链的变化。猪L3期（LL 3）A的线粒体酶活性、醌含量和复合物II亚基组成。猪幼虫LL 3线粒体的QFR活性（160 nmol/min/mg）高于A.猪在其他阶段（L3：类似于80 nmol/min/mg;成人：类似于70 nmol/min/mg）。LL 3线粒体中的泛醌含量比玫瑰醌更丰富（类似于1.8 nmol/mg对类似于0.9 nmol/mg）。有趣的是，双向电泳分析结果表明，LL 3线粒体含有幼虫Fp（FPL）和成虫Fp（FPA），比例为1：0.56，大多数LL 3 CybS亚基为成虫形式（CybS（A））。这清楚地表明，复合物II的重排开始于锚CybS亚基同种型的变化，随后是Fp亚基的类似变化。(C)2007爱思唯尔爱尔兰有限公司保留所有权利。
The mitochondrial metabolic pathway of the parasitic nematode Ascaris suum changes dramatically during its life cycle, to adapt to changes in the environmental oxygen concentration. We previously showed that A. suum mitochondria express stage-specific isoforms of complex II (succinate-ubiquinone reductase: SQR/quinol-fumarate reductase: QFR). The flavoprotein (Fp) and small subunit of cytochrome b (CybS) in adult complex II differ from those of infective third stage larval (L3) complex II. However, there is no difference in the iron-sulfur cluster (Ip) or the large subunit of cytochrome b (CybL) between adult and L3 isoforms of complex II. In the present study, to clarify the changes that occur in the respiratory chain of A. suum larvae during their migration in the host, we examined enzymatic activity, quinone content and complex II subunit composition in mitochondria of lung stage L3 (LL3) A. suum larvae. LL3 mitochondria showed higher QFR activity (similar to 160 nmol/min/mg) than mitochondria of A. suum at other stages (L3: similar to 80 nmol/min/mg; adult: similar to 70 nmol/min/mg). Ubiquinone content in LL3 mitochondria was more abundant than rhodoquinone (similar to 1.8 nmol/mg versus similar to 0.9 nmol/mg). Interestingly, the results of two-dimensional bule-native/sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses showed that LL3 mitochondria contained larval Fp (FPL) and adult Fp (FPA) at a ratio of 1:0.56, and that most LL3 CybS subunits were of the adult form (CybS(A)). This clearly indicates that the rearrangement of complex II begins with a change in the isoform of the anchor CybS subunit, followed by a similar change in the Fp subunit. (C) 2007 Elsevier Ireland Ltd. All rights reserved.