Sequence requirements for the export of the Plasmodium falciparum Maurer's clefts protein REX2
Sequence requirements for the export of the Plasmodium falciparum Maurer's clefts protein REX2
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DOI：
10.1111/j.1365-2958.2008.06582.x
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发表时间：
2009-02-01
影响因子：
3.6
通讯作者：
Spielmann, Tobias
中科院分区：
文献类型：
--
作者：
Haase, Silvia;Herrmann, Susann;Spielmann, Tobias
一个短的基序被称为疟原虫输出元件（PEXEL）或液泡靶向信号（VTS）表征疟原虫蛋白输出到宿主细胞。这些蛋白介导宿主细胞修饰，对寄生虫的生存和毒力至关重要。然而，一些pexel阴性输出蛋白表明，目前预测的疟疾输出蛋白并不完整，而且尚不清楚这些蛋白是否以及如何与pexel阳性输出相关。本研究表明，peexel阴性输出蛋白REX2（环输出蛋白2）的n端10个氨基酸是其靶向所必需的，该区域的单点突变消除了输出。此外，我们发现REX2跨膜结构域对于输出也是必不可少的，并且与n端区域一起足以促进另一种蛋白质的输出。不相关的peel -阴性输出蛋白SBP1（骨骼结合蛋白1）的n端区域和跨膜结构域可以在功能上取代REX2中的相应区域，这表明这些序列特征也存在于其他peel -阴性输出蛋白中。与PEXEL蛋白类似，我们发现REX2被加工，但相反，没有检测到n端乙酰化的证据。
A short motif termed Plasmodium export element (PEXEL) or vacuolar targeting signal (VTS) characterizes Plasmodium proteins exported into the host cell. These proteins mediate host cell modifications essential for parasite survival and virulence. However, several PEXEL-negative exported proteins indicate that the currently predicted malaria exportome is not complete and it is unknown whether and how these proteins relate to PEXEL-positive export. Here we show that the N-terminal 10 amino acids of the PEXEL-negative exported protein REX2 (ring-exported protein 2) are necessary for its targeting and that a single-point mutation in this region abolishes export. Furthermore we show that the REX2 transmembrane domain is also essential for export and that together with the N-terminal region it is sufficient to promote export of another protein. An N-terminal region and the transmembrane domain of the unrelated PEXEL-negative exported protein SBP1 (skeleton-binding protein 1) can functionally replace the corresponding regions in REX2, suggesting that these sequence features are also present in other PEXEL-negative exported proteins. Similar to PEXEL proteins we find that REX2 is processed, but in contrast, detect no evidence for N-terminal acetylation.