Bioenergetics and Molecular Genetics Lab, Centro de Investigacion en Alimentacion y Desarrollo, A. C. Carretera a Ejido La Victoria Km 0.6, PO Box 1735, 83000, Hermosillo, Sonora, Mexico.
Department of Molecular Genetics, Instituto de Fisiologia Celular, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, PO Box 70-242, Mexico City, Mexico.
J Bioenerg Biomembr. 2019 Apr;51(2):103-119. doi: 10.1007/s10863-019-09789-5. Epub 2019 Feb 22.
Mitochondrial uncoupling proteins (UCP) transport protons from the intermembrane space to the mitochondrial matrix uncoupling oxidative phosphorylation. In mammals, these proteins have been implicated in several cellular functions ranging from thermoregulation to antioxidant defense. In contrast, their invertebrate homologs have been much less studied despite the great diversity of species. In this study, two transcripts encoding mitochondrial uncoupling proteins were, for the first time, characterized in crustaceans. The white shrimp Litopenaeus vannamei transcript LvUCP4 is expressed in all tested shrimp tissues/organs, and its cDNA includes a coding region of 954 bp long which encodes a deduced protein 318 residues long and a predicted molecular weight of 35.3 kDa. The coding region of LvUCP5 transcript is 906 bp long, encodes a protein of 302 residues with a calculated molecular weight of 33.17 kDa. Both proteins share homology with insect UCPs, their predicted structures show the conserved motifs of the mitochondrial carrier proteins and were confirmed to be located in the mitochondria through a Western blot analysis. The genic expression of LvUCP4 and LvUCP5 was evaluated in shrimp at oxidative stress conditions and results were compared to some antioxidant enzymes to infer about their antioxidant role. LvUCP4 and LvUCP5 genes expression did not change during hypoxia/re-oxygenation, and no coordinated responses were detected with antioxidant enzymes at the transcriptional level. Results confirmed UCPs as the first uncoupling mechanism reported in this species, but their role in the oxidative stress response remains to be confirmed.
线粒体解偶联蛋白（UCP）将质子从膜间空间转运到线粒体基质中，从而解耦氧化磷酸化。在哺乳动物中，这些蛋白质与多种细胞功能有关，从体温调节到抗氧化防御。相比之下，尽管物种多样性很大，但它们的无脊椎动物同源物的研究要少得多。在这项研究中，首次在甲壳类动物中鉴定了两种编码线粒体解偶联蛋白的转录本。白对虾 Litopenaeus vannamei 的 LvUCP4 转录本在所有测试的虾组织/器官中表达，其 cDNA 包括一个 954bp 长的编码区，编码一个 318 个氨基酸的推导蛋白和一个预测的 35.3kDa 分子量。LvUCP5 转录本的编码区长 906bp，编码一个 302 个氨基酸的蛋白，计算分子量为 33.17kDa。这两种蛋白质与昆虫 UCPs 具有同源性，它们的预测结构显示了线粒体载体蛋白的保守基序，并通过 Western blot 分析证实位于线粒体中。在氧化应激条件下评估了 LvUCP4 和 LvUCP5 的基因表达，并将结果与一些抗氧化酶进行比较，以推断它们的抗氧化作用。在低氧/再氧化期间，LvUCP4 和 LvUCP5 基因的表达没有改变，并且在转录水平上没有检测到与抗氧化酶的协调反应。结果证实 UCPs 是该物种中报道的第一种解偶联机制，但它们在氧化应激反应中的作用仍有待证实。
