Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Bethesda, Maryland, United States of America.
PLoS One. 2011 Jan 14;6(1):e16156. doi: 10.1371/journal.pone.0016156.
In this report, we demonstrate the existence of the ubiquitin fold modifier-1 (Ufm1) and its conjugation pathway in trypanosomatid parasite Leishmania donovani. LdUfm1 is activated by E1-like enzyme LdUba5. LdUfc1 (E2) specifically interacted with LdUfm1 and LdUba5 to conjugate LdUfm1 to proteinaceous targets. Mass spectrometry analysis revealed that LdUfm1 is conjugated to Leishmania protein targets that are associated with mitochondria. Immunofluorescence experiments showed that Leishmania Ufm1, Uba5 and Ufc1 are associated with the mitochondria. The demonstration that all the components of this system as well as the substrates are associated with mitochondrion suggests it may have physiological roles not yet described in any other organism. Overexpression of a non-conjugatable form of LdUfm1 and an active site mutant of LdUba5 resulted in reduced survival of Leishmania in the macrophage. Since mitochondrial activities are developmentally regulated in the life cycle of trypanosomatids, Ufm1 mediated modifications of mitochondrial proteins may be important in such regulation. Thus, Ufm1 conjugation pathway in Leishmania could be explored as a potential drug target in the control of Leishmaniasis.
在本报告中，我们证明了泛素折叠修饰蛋白 1（Ufm1）及其缀合途径在利什曼原虫寄生虫利什曼原虫中的存在。LdUfm1 被类似 E1 的酶 LdUba5 激活。LdUfc1（E2）特异性与 LdUfm1 和 LdUba5 相互作用，将 LdUfm1 缀合到蛋白质靶标上。质谱分析显示，LdUfm1 与与线粒体相关的利什曼蛋白靶标缀合。免疫荧光实验表明，利什曼 Ufm1、Uba5 和 Ufc1 与线粒体相关。该系统的所有成分以及底物都与线粒体相关的证明表明，它可能具有在其他任何生物体中尚未描述的生理作用。过量表达非缀合形式的 LdUfm1 和 LdUba5 的活性位点突变体导致巨噬细胞中利什曼原虫的存活率降低。由于线粒体的活性在动基体生物的生命周期中受到发育调控，因此 Ufm1 介导的线粒体蛋白修饰可能在这种调控中很重要。因此，利什曼原虫中的 Ufm1 缀合途径可作为控制利什曼病的潜在药物靶点进行探索。
