Sequence alignment of conserved signature motifs predicts the existence of the uncoupling protein 5 (UCP5)/brain mitochondrial carrier protein (BMCP1) homologue in Drosophila melanogaster. Here we demonstrate the functional characterization of the Drosophila melanogaster UCP5 protein (DmUCP5) in the heterologous yeast system, the first insect UCP reported to date. We show that physiological levels of DmUCP5 expression are responsible for an increase in state 4 respiration rates and a decrease in mitochondrial membrane potential. Furthermore, similar to UCP1, UCP2, and UCP3, the uncoupling activity of DmUCP5 is augmented by fatty acids and inhibited by the purine nucleotide GDP. Thus, DmUCP5 shares the mechanisms known to regulate the UCPs characterized to date. A lack of growth inhibition observed in DmUCP5 expressing yeast is consistent with the notion that physiological uncoupling has a minimal effect on cell growth. Finally, semiquantitative RT-PCR analysis shows a distinctive pattern of DmUCP5 expression predominantly localized in the adult head, similar to the expression pattern of its mammalian homologues. The conserved regulation of the expression of this gene from mammals to fruit flies suggests a role for UCP5 in the brain.

中文翻译：

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果蝇线粒体解偶联蛋白的功能表征。

保守签名基序的序列比对预测果蝇中存在解偶联蛋白5（UCP5）/脑线粒体载体蛋白（BMCP1）同源物。在这里，我们证明了果蝇果蝇UCP5蛋白（DmUCP5）在异源酵母系统中的功能表征，这是迄今为止报道的第一种昆虫UCP。我们显示DmUCP5表达的生理水平是造成状态4呼吸速率增加和线粒体膜电位降低的原因。此外，类似于UCP1，UCP2和UCP3，DmUCP5的解偶联活性通过脂肪酸增强，并被嘌呤核苷酸GDP抑制。因此，DmUCP5具有已知的机制来调节迄今表征的UCP。在表达DmUCP5的酵母中缺乏生长抑制现象与生理解偶联对细胞生长的影响最小的观点一致。最后，半定量RT-PCR分析显示了DmUCP5表达的独特模式，主要定位于成年头部，与其哺乳动物同源基因的表达模式相似。该基因从哺乳动物到果蝇的表达的保守调节表明UCP5在脑中的作用。