Post-transcriptional control of tubulin biosynthesis during leishmanial differentiation.
Post-transcriptional control of tubulin biosynthesis during leishmanial differentiation.
复制标题
利什曼原虫分化过程中微管蛋白生物合成的转录后控制。
作者：
Wallach,M;Fong,D;Chang,KP
在细胞分化过程中，基因表达的控制可以在不同的水平上发生。利用离体培养系统1，我们研究了寄生性原生动物墨西哥利什曼原虫（Leishmania mexicana）分化过程中蛋白质的生物合成。有两个发展阶段的生活史，这和类似的寄生虫：在白蛉肠道和非能动的细胞内无鞭毛体在哺乳动物巨噬细胞的能动的细胞外前鞭毛体。后者的细胞内寄生导致人类利什曼病，这种疾病在世界许多地方仍然广泛存在2。在利什曼原虫从一个阶段分化到另一个阶段，我们观察到微管蛋白生物合成的变化，伴随着这些寄生虫的鞭毛和膜下微管长度的形态变化3。除了少数例外，已知微管蛋白生物合成在其他真核系统中受转录控制6 -12。在此，我们利用来自无鞭毛体和前鞭毛体的总细胞poly（A）+RNA在体外翻译系统中检测了利什曼原虫分化过程中的蛋白质合成。与我们的预期相反，结果表明在我们的宿主-寄生虫培养系统中，利什曼原虫分化期间微管蛋白生物合成受到转录后控制。
Controls of gene expression can occur at different levels during cell differentiation. Using anin vitroculture system1, we have studied protein biosynthesis during the differentiation of a parasitic protozoan,Leishmania mexicana. There are two developmental stages in the life cycle of this and similar parasites: motile extracellular promastigotes in the sandfly gut and non-motile intracellular amastigotes in the mammalian macrophages. Intracellular parasitism by the latter results in human leishmaniases, diseases still widespread in many parts of the world2. During leishmanial differentiation from one stage to the other, we observed changes in tubulin biosynthesis, concomitant with the morphological changes of these parasites in the length of their flagella and subpellicular microtubules3. With few exceptions4,5tubulin biosynthesis is known to be under transcriptional control in other eukaryotic systems6–12. Here we have examined the protein synthesis during leishmanial differentiation inin vitrotranslation systems using total cellular poly(A)+RNA from amastigotes and promastigotes. Contrary to our expectations, the results indicate a post-transcriptional control for the tubulin biosynthesis during leishmanial differentiation in our host–parasite culture system.