NADH dehydrogenase of Trypanosoma brucei is important for efficient acetate production in bloodstream forms.
NADH dehydrogenase of Trypanosoma brucei is important for efficient acetate production in bloodstream forms.
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DOI：
10.1016/j.molbiopara.2016.10.001
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发表时间：
2017-01
影响因子：
1.5
通讯作者：
Schnaufer A
中科院分区：
文献类型：
--
作者：
Surve SV;Jensen BC;Heestand M;Mazet M;Smith TK;Bringaud F;Parsons M;Schnaufer A
NDH 2的各种遗传突变体是在布氏锥虫的血液中产生的。NDH 2无效突变体显示出生长的显著降低。在复合物I缺陷背景下的NDH 2消融导致严重的生长限制。经过长期培养，寄生虫部分补偿NDH 2缺乏。NDH 2的损失导致乙酸盐减少，可能导致生长缺陷。在细长的血流形式中，布氏锥虫线粒体的许多功能受到抑制。线粒体复合物I的多个组分，NADH：泛醌氧化还原酶，在这个阶段表达，但通过复合物I的电子转移不是必需的。在这里，我们调查的寄生虫的第二个NADH的作用：泛醌氧化还原酶，NDH 2，这是由一个单一的亚基，也定位到的peption。虽然诱导敲除NDH 2在血流形式中具有适度的生长效果，但NDH 2无效突变体以及在复合物I缺陷背景中的诱导敲除显示出更大的生长减少。改变NAD+/NADH平衡将直接或间接影响许多过程，包括乙酸盐的生产。事实上，NDH 2的丢失导致乙酸水平降低，而乙酸是T型血中几种基本途径所必需的。布氏杆菌，这可能导致观察到的生长缺陷。总之，我们的研究表明，NDH 2是重要的，但不是必需的，在增殖的血液形式的T。brucei，认为线粒体NAD+/NADH平衡在这个阶段很重要，即使线粒体本身并不积极参与ATP的产生。
Various genetic mutants of NDH2 were created in bloodstream form Trypanosoma brucei. NDH2 null mutants showed a substantial reduction in growth. NDH2 ablation in a complex I deficient background led to severe growth restriction. Upon prolonged culture, parasites partially compensated for NDH2 deficiency. Loss of NDH2 led to reduced acetate, potentially contributing to the growth defect. In the slender bloodstream form, Trypanosoma brucei mitochondria are repressed for many functions. Multiple components of mitochondrial complex I, NADH:ubiquinone oxidoreductase, are expressed in this stage, but electron transfer through complex I is not essential. Here we investigate the role of the parasite’s second NADH:ubiquinone oxidoreductase, NDH2, which is composed of a single subunit that also localizes to the mitochondrion. While inducible knockdown of NDH2 had a modest growth effect in bloodstream forms, NDH2 null mutants, as well as inducible knockdowns in a complex I deficient background, showed a greater reduction in growth. Altering the NAD+/NADH balance would affect numerous processes directly and indirectly, including acetate production. Indeed, loss of NDH2 led to reduced levels of acetate, which is required for several essential pathways in bloodstream form T. brucei and which may have contributed to the observed growth defect. In conclusion our study shows that NDH2 is important, but not essential, in proliferating bloodstream forms of T. brucei, arguing that the mitochondrial NAD+/NADH balance is important in this stage, even though the mitochondrion itself is not actively engaged in the generation of ATP.