Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas Alfredo Lanari, Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
Exp Parasitol. 2012 Apr;130(4):408-11. doi: 10.1016/j.exppara.2012.01.020. Epub 2012 Feb 7.
Adenylate kinases are key enzymes involved in cell energy management. Trypanosomatid organisms have the largest number of isoforms found in a single cell, constituting a major difference with the mammalian hosts. In this work we study an adenylate kinase, TcADK3, the only Trypanosoma cruzi protein harboring the putative peroxisomal (glycosomal) targeting signal, "-CKL". Parasites expressing GFP fused to TcADK3 showed a strong fluorescence in the glycosomes. The same result was obtained when the tripeptide "-CKL" was added at the C-terminus of the GFP, demonstrating that this signal is necessary and sufficient for targeting proteins to glycosomes. When this tripeptide was removed from the GFP-TcADK3 fusion protein, the fluorescence was re-localized in the cytoplasm. The CKL signal could be used for targeting foreign proteins to the glycosomes. This model also provides a useful tool to study glycosomes dynamics, morphology or number in living parasites in any stage of the life cycle.
腺嘌呤激酶是参与细胞能量管理的关键酶。原生动物有在单个细胞中发现的最多的同工酶种类，这是与哺乳动物宿主的主要区别。在这项工作中，我们研究了一种腺嘌呤激酶，TcADK3，它是唯一一种携带有假定过氧化物酶体（糖酶体）靶向信号 "-CKL" 的克氏锥虫蛋白。表达 GFP 融合蛋白的寄生虫在糖酶体中显示出强烈的荧光。当 GFP 的 C 末端添加三肽 "-CKL" 时，也得到了相同的结果，这表明该信号对于将蛋白质靶向糖酶体是必要且充分的。当从 GFP-TcADK3 融合蛋白中去除这个三肽时，荧光重新定位于细胞质中。这个三肽信号可用于将外源蛋白靶向糖酶体。该模型还为在生命周期的任何阶段研究活寄生虫中的糖酶体动力学、形态或数量提供了一个有用的工具。
