Identification and expression of the protein ubiquitination system in Giardia intestinalis
Identification and expression of the protein ubiquitination system in Giardia intestinalis
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DOI：
10.1007/s00436-007-0458-2
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发表时间：
2007-06-01
影响因子：
2
通讯作者：
Wasserman, Moises
中科院分区：
文献类型：
--
作者：
Gallego, Eva;Alvarado, Magda;Wasserman, Moises
贾第鞭毛虫是一种单细胞真核微生物，被认为是最早分化的真核生物之一，因此是研究调控系统进化的有吸引力的模型。贾第虫在其整个生命周期中有两种不同的形式，包囊和滋养体，并根据环境信号从一种变化到另一种。这两个分化过程涉及差异基因表达以及可能由泛素/蛋白酶体系统介导的快速和特异的蛋白质周转。这项工作的目的是寻找遍在蛋白化系统中未报道的成分，并通过实验证明它们在寄生虫中和两个分化过程中的表达。我们发现G.并分析了泛素基因的转录，以及在成囊和脱囊过程中激活（E1），缀合（E2）和连接酶（E3）泛素酶的转录。在寄生虫的分化过程中持续存在一个恒定的泛素表达，而在研究中的其他基因中观察到转录的变化。
Giardia intestinalis is a single-cell eukaryotic microorganism, regarded as one of the earliest divergent eukaryotes and thus an attractive model to study the evolution of regulatory systems. Giardia has two different forms throughout its life cycle, cyst and trophozoite, and changes from one to the other in response to environmental signals. The two differentiation processes involve a differential gene expression as well as a quick and specific protein turnover that may be mediated by the ubiquitin/proteasome system. The aim of this work was to search for unreported components of the ubiquitination system and to experimentally demonstrate their expression in the parasite and during the two differentiation processes. We found activity of protein ubiquitination in G. intestinalis trophozoites and analyzed the transcription of the ubiquitin gene, as well as that of the activating (E1), conjugating (E2), and ligase (E3) ubiquitin enzymes during encystation and excystation. A constant ubiquitin expression persisted during the parasite's differentiation processes, whereas variation in transcription was observed in the other genes under study.