A differential role for actin during the life cycle of Trypanosoma brucei
A differential role for actin during the life cycle of Trypanosoma brucei
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DOI：
10.1038/sj.emboj.7600094
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发表时间：
2004-02-25
期刊：
影响因子：
11.4
通讯作者：
Nolan, DP
中科院分区：
文献类型：
--
作者：
García-Salcedo, JA;Pérez-Morga, D;Nolan, DP
肌动蛋白在布氏锥虫的血流和前循环形式中以相似的水平但在不同的位置表达。在血流形式中，肌动蛋白与高度极化的内吞途径共定位，而在原环形式中，它分布在整个细胞中。RNA干扰表明，在血流形式中，肌动蛋白是一种必需的蛋白质。肌动蛋白的耗尽导致细胞分裂的快速停滞，终止从鞭毛口袋膜的囊泡交通导致的口袋的总扩大，内吞活性的损失，并最终细胞死亡。这些结果表明，肌动蛋白是需要从鞭毛口袋膜，这是在内吞途径的第一步形成的包被囊泡。虽然损失的肌动蛋白在procyclic细胞并不影响增长，高尔基体的反式区域变得扭曲和扩大，似乎引起了一个异质性的人口囊泡。然而，鞭毛口袋没有受到影响。这些研究结果表明，锥虫有不同的功能要求肌动蛋白在血流和生命周期的前循环阶段。
Actin is expressed at similar levels but in different locations in bloodstream and procyclic forms of Trypanosoma brucei. In bloodstream forms actin colocalizes with the highly polarized endocytic pathway, whereas in procyclic forms it is distributed throughout the cell. RNA interference demonstrated that in bloodstream forms, actin is an essential protein. Depletion of actin resulted in a rapid arrest of cell division, termination of vesicular traffic from the flagellar pocket membrane leading to gross enlargement of the pocket, loss of endocytic activity and eventually cell death. These results indicate that actin is required for the formation of coated vesicles from the flagellar pocket membrane, which is the first step in the endocytic pathway. Although loss of actin in procyclic cells did not affect growth, the trans region of the Golgi became distorted and enlarged and appeared to give rise to a heterogeneous population of vesicles. However, the flagellar pocket was not affected. These findings suggest that trypanosomes have different functional requirements for actin during the bloodstream and procyclic phases of the life cycle.