The DotA protein from Legionella pneumophila is secreted by a novel process that requires the Dot/Icm transporter
The DotA protein from Legionella pneumophila is secreted by a novel process that requires the Dot/Icm transporter
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DOI：
10.1093/emboj/20.21.5962
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发表时间：
2001-11-01
期刊：
影响因子：
11.4
通讯作者：
Roy, CR
中科院分区：
文献类型：
--
作者：
Nagai, H;Roy, CR
嗜肺军团菌需要dot/icm基因在真核宿主细胞内创造一个细胞器，以支持细菌的复制。dot/icm基因被预测编码IV型相关的分泌器。然而，还没有发现需要dot/icm基因进行分泌的蛋白质。在这项研究中，我们表明，DotA蛋白，这是以前被发现是一个多位膜蛋白，分泌的点/Icm转运到培养上清液。纯化分泌的DotA蛋白，纯化蛋白的N-末端测序显示，在分泌之前从DotA中除去了19个氨基酸的前导肽。胞外DotA蛋白在膜泡中不断裂。通过电子显微镜观察含有分泌的DotA蛋白的结构，其形状类似于中空环。这些数据表明，大的多位膜蛋白DotA是由嗜肺军团菌分泌的一个独特的过程。这代表了由dot/icm编码的装置分泌的第一个靶标，并证明该转运蛋白能够分泌蛋白质。
Legionella pneumophila requires the dot/icm genes to create an organelle inside eukaryotic host cells that will support bacterial replication. The dot/icm genes are predicted to encode a type IV-related secretion apparatus. However, no proteins have been identified that require the dot/icm genes for secretion. In this study we show that the DotA protein, which was previously found to be a polytopic membrane protein, is secreted by the Dot/Icm transporter into culture supernatants. Secreted DotA protein was purified and N-terminal sequencing of the purified protein revealed that a 19 amino acid leader peptide is removed from DotA prior to secretion. Extracellular DotA protein did not fractionate in membrane vesicles. Structures containing secreted DotA protein were visualized by electron microscopy and were shaped like hollow rings. These data indicate that the large poly topic membrane protein DotA is secreted from L.pneumophilaby a unique process. This represents the first target secreted by the dot/icm-encoded apparatus and demonstrates that this transporter is competent for protein secretion.